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95-529: The CIF also housed computers and other electronic equipment for reduction of telemetry data, analysis, and transmission to other NASA centers. The three-story structure of approximately 134,335 sq ft (12,480.1 m) just west of the KSC Headquarters Building was one of the most distinctive buildings in the KSC Industrial Area with its rooftop array of various antennas . The CIF

190-499: A base of nickel above those required to cause a transition from internal to external modes of oxidation, and by selecting solutes (silicon and magnesium) that preferentially oxidize to form a diffusion-barrier, and hence oxidation-inhibiting films. Type N thermocouples are suitable alternative to type K for low-oxygen conditions where type K is prone to green rot. They are suitable for use in vacuum, inert atmospheres, oxidizing atmospheres, or dry reducing atmospheres. They do not tolerate

285-485: A base station. Telemetry hardware is useful for tracking persons and property in law enforcement. An ankle collar worn by convicts on probation can warn authorities if a person violates the terms of his or her parole , such as by straying from authorized boundaries or visiting an unauthorized location. Telemetry has also enabled bait cars , where law enforcement can rig a car with cameras and tracking equipment and leave it somewhere they expect it to be stolen. When stolen

380-430: A decimeter band and PPM on a centimeter band. Telemetry has been used by weather balloons for transmitting meteorological data since 1920. Telemetry is used to transmit drilling mechanics and formation evaluation information uphole, in real time, as a well is drilled. These services are known as Measurement while drilling and Logging while drilling . Information acquired thousands of feet below ground, while drilling,

475-513: A device that packages the reference junction block (with T ref thermometer), voltmeter, and equation solver. The Seebeck effect refers to the development of an electromotive force across two points of an electrically conducting material when there is a temperature difference between those two points. Under open-circuit conditions where there is no internal current flow, the gradient of voltage ( ∇ V {\displaystyle \scriptstyle {\boldsymbol {\nabla }}V} )

570-841: A distance. In 1906 a set of seismic stations were built with telemetering to the Pulkovo Observatory in Russia. In 1912, Commonwealth Edison developed a system of telemetry to monitor electrical loads on its power grid. The Panama Canal (completed 1913–1914) used extensive telemetry systems to monitor locks and water levels. Wireless telemetry made early appearances in the radiosonde , developed concurrently in 1930 by Robert Bureau in France and Pavel Molchanov in Russia . Molchanov's system modulated temperature and pressure measurements by converting them to wireless Morse code . The German V-2 rocket used

665-507: A major role in disease prevention and precision irrigation. These stations transmit parameters necessary for decision-making to a base station: air temperature and relative humidity , precipitation and leaf wetness (for disease prediction models), solar radiation and wind speed (to calculate evapotranspiration ), water deficit stress (WDS) leaf sensors and soil moisture (crucial to irrigation decisions). Because local micro-climates can vary significantly, such data needs to come from within

760-457: A much higher thermal conductivity than the alloys generally used in thermocouple constructions, and so it is necessary to exercise extra care with thermally anchoring type-T thermocouples. A similar composition is found in the obsolete Type U in the German specification DIN 43712:1985-01. Types B, R, and S thermocouples use platinum or a platinum/ rhodium alloy for each conductor. These are among

855-442: A multi-wire cable for carrying many thermocouple circuits. With expensive noble metal thermocouples, the extension wires may even be made of a completely different, cheaper material that mimics the standard type over a reduced temperature range. Thermocouples are often used at high temperatures and in reactive furnace atmospheres. In this case, the practical lifetime is limited by thermocouple aging. The thermoelectric coefficients of

950-529: A precise E ( T ) {\displaystyle \scriptstyle E(T)} curve, independent of any other details. In reality, thermocouples are affected by issues such as alloy manufacturing uncertainties, aging effects, and circuit design mistakes/misunderstandings. A common error in thermocouple construction is related to cold junction compensation. If an error is made on the estimation of T r e f {\displaystyle T_{\mathrm {ref} }} , an error will appear in

1045-430: A principal object of constant commercial telemetry. This typically includes monitoring of tank farms in gasoline refineries and chemical plants—and distributed or remote tanks, which must be replenished when empty (as with gas station storage tanks, home heating oil tanks, or ag-chemical tanks at farms), or emptied when full (as with production from oil wells, accumulated waste products, and newly produced fluids). Telemetry

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1140-410: A ranging device (the rangefinding telemeter ), by the late 19th century the same term had been in wide use by electrical engineers applying it refer to electrically operated devices measuring many other quantities besides distance (for instance, in the patent of an "Electric Telemeter Transmitter" ). General telemeters included such sensors as the thermocouple (from the work of Thomas Johann Seebeck ),

1235-542: A relatively flat voltage curve near room temperature, meaning that a large uncertainty in a room-temperature T r e f {\displaystyle T_{\mathrm {ref} }} translates to only a small error in T s e n s e {\displaystyle T_{\mathrm {sense} }} . Junctions should be made in a reliable manner, but there are many possible approaches to accomplish this. For low temperatures, junctions can be brazed or soldered; however, it may be difficult to find

1330-465: A route truck or to a headquarters. This data could be used for a variety of purposes, such as eliminating the need for drivers to make a first trip to see which items needed to be restocked before delivering the inventory. Retailers also use RFID tags to track inventory and prevent shoplifting. Most of these tags passively respond to RFID readers (e.g., at the cashier), but active RFID tags are available which periodically transmit location information to

1425-431: A sacrificial titanium wire) can be added. Alternatively, additional oxygen can be introduced into the thermowell. Another option is using a different thermocouple type for the low-oxygen atmospheres where green rot can occur; a type N thermocouple is a suitable alternative. Type M (82%Ni/18% Mo –99.2%Ni/0.8% Co , by weight) are used in vacuum furnaces for the same reasons as with type C (described below). Upper temperature

1520-419: A single thermocouple junction. Power generation using multiple thermocouples, as in a thermopile , is common. The standard configuration of a thermocouple is shown in the figure. The dissimilar conductors contact at the measuring (aka hot) junction and at the reference (aka cold) junction. The thermocouple is connected to the electrical system at its reference junction. The figure shows the measuring junction on

1615-404: A suitable flux and this may not be suitable at the sensing junction due to the solder's low melting point. Reference and extension junctions are therefore usually made with screw terminal blocks . For high temperatures, the most common approach is the spot weld or crimp using a durable material. One common myth regarding thermocouples is that junctions must be made cleanly without involving

1710-582: A system of primitive multiplexed radio signals called "Messina" to report four rocket parameters, but it was so unreliable that Wernher von Braun once claimed it was more useful to watch the rocket through binoculars. In the US and the USSR, the Messina system was quickly replaced with better systems; in both cases, based on pulse-position modulation (PPM). Early Soviet missile and space telemetry systems which were developed in

1805-448: A thermocouple wire type is often described by its chemical composition, the actual aim is to produce a pair of wires that follow a standardized E ( T ) {\displaystyle \scriptstyle E(T)} curve. Impurities affect each batch of metal differently, producing variable Seebeck coefficients. To match the standard behaviour, thermocouple wire manufacturers will deliberately mix in additional impurities to "dope"

1900-570: A third metal, to avoid unwanted added EMFs. This may result from another common misunderstanding that the voltage is generated at the junction. In fact, the junctions should in principle have uniform internal temperature; therefore, no voltage is generated at the junction. The voltage is generated in the thermal gradient, along the wire. A thermocouple produces small signals, often microvolts in magnitude. Precise measurements of this signal require an amplifier with low input offset voltage and with care taken to avoid thermal EMFs from self-heating within

1995-553: A wide range of temperatures. In contrast to most other methods of temperature measurement, thermocouples are self-powered and require no external form of excitation. The main limitation with thermocouples is accuracy; system errors of less than one degree Celsius (°C) can be difficult to achieve. Thermocouples are widely used in science and industry. Applications include temperature measurement for kilns , gas turbine exhaust, diesel engines , and other industrial processes. Thermocouples are also used in homes, offices and businesses as

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2090-479: Is 0 to 2315 °C, which can be extended to 2760 °C in inert atmosphere and to 3000 °C for brief measurements. Pure tungsten at high temperatures undergoes recrystallization and becomes brittle. Therefore, types C and D are preferred over type G in some applications. In presence of water vapor at high temperature, tungsten reacts to form tungsten(VI) oxide , which volatilizes away, and hydrogen. Hydrogen then reacts with tungsten oxide, after which water

2185-456: Is also recorded so the team can assess driver performance and (in case of an accident) the FIA can determine or rule out driver error as a possible cause. Later developments include two-way telemetry which allows engineers to update calibrations on the car in real time (even while it is out on the track). In Formula One, two-way telemetry surfaced in the early 1990s and consisted of a message display on

2280-555: Is also used for the remote monitoring of substations and their equipment. For data transmission, phase line carrier systems operating on frequencies between 30 and 400 kHz are sometimes used. In falconry , "telemetry" means a small radio transmitter carried by a bird of prey that will allow the bird's owner to track it when it is out of sight. Telemetry is used in testing hostile environments which are dangerous to humans. Examples include munitions storage facilities, radioactive sites, volcanoes, deep sea, and outer space. Telemetry

2375-427: Is calculated, then the function E ( T ) {\displaystyle \scriptstyle E(T)} is searched for a matching value. The argument where this match occurs is the value of T s e n s e {\displaystyle \scriptstyle T_{\mathrm {sense} }} : Thermocouples ideally should be very simple measurement devices, with each type being characterized by

2470-585: Is derived from the Greek roots tele , 'far off', and metron , 'measure'. Systems that need external instructions and data to operate require the counterpart of telemetry: telecommand . Although the term commonly refers to wireless data transfer mechanisms (e.g., using radio , ultrasonic, or infrared systems), it also encompasses data transferred over other media such as a telephone or computer network , optical link or other wired communications like power line carriers. Many modern telemetry systems take advantage of

2565-581: Is directly proportional to the gradient in temperature ( ∇ T {\displaystyle \scriptstyle {\boldsymbol {\nabla }}T} ): where S ( T ) {\displaystyle S(T)} is a temperature-dependent material property known as the Seebeck coefficient . The standard measurement configuration shown in the figure shows four temperature regions and thus four voltage contributions: The first and fourth contributions cancel out exactly, because these regions involve

2660-519: Is especially useful when the clinical examination is limited. Telemetry is used to study wildlife, and has been useful for monitoring threatened species at the individual level. Animals under study can be outfitted with instrumentation tags, which include sensors that measure temperature, diving depth and duration (for marine animals), speed and location (using GPS or Argos packages). Telemetry tags can give researchers information about animal behavior, functions, and their environment. This information

2755-501: Is limited to 1400 °C. It is less commonly used than other types. Type N ( Nicrosil – Nisil ) thermocouples are suitable for use between −270 °C and +1300 °C, owing to its stability and oxidation resistance. Sensitivity is about 39 μV/°C at 900 °C, slightly lower compared to type K. Designed at the Defence Science and Technology Organisation (DSTO) of Australia, by Noel A. Burley, type-N thermocouples overcome

2850-428: Is non-magnetic). Hydrogen in the atmosphere is the usual cause of green rot. At high temperatures, it can diffuse through solid metals or an intact metal thermowell. Even a sheath of magnesium oxide insulating the thermocouple will not keep the hydrogen out. Green rot does not occur in atmospheres sufficiently rich in oxygen, or oxygen-free. A sealed thermowell can be filled with inert gas, or an oxygen scavenger (e.g.

2945-402: Is non-magnetic. Wide range is −270 °C to +740 °C and narrow range is −110 °C to +140 °C. Type J ( iron – constantan ) has a more restricted range (−40 °C to +1200 °C) than type K but higher sensitivity of about 50 μV/°C. The Curie point of the iron (770 °C) causes a smooth change in the characteristic, which determines the upper-temperature limit. Note,

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3040-458: Is not sufficient to just measure V {\displaystyle \scriptstyle V} . The temperature at the reference junctions T r e f {\displaystyle \scriptstyle T_{\mathrm {ref} }} must also be known. Two strategies are often used here: In both cases the value V + E ( T r e f ) {\displaystyle \scriptstyle V+E(T_{\mathrm {ref} })}

3135-465: Is not suitable for direct insertion into metallic protecting tubes. Long term high temperature exposure causes grain growth which can lead to mechanical failure and a negative calibration drift caused by Rhodium diffusion to pure platinum leg as well as from Rhodium volatilization. This type has the same uses as type S, but is not interchangeable with it. Type S (90%Pt/10%Rh–Pt, by weight) thermocouples, similar to type R, are used up to 1600 °C. Before

3230-411: Is pulled partly out of a furnace—as the sensor is pulled back, aged sections may see exposure to increased temperature gradients from hot to cold as the aged section now passes through the cooler refractory area, contributing significant error to the measurement. Likewise, an aged thermocouple that is pushed deeper into the furnace might sometimes provide a more accurate reading if being pushed further into

3325-635: Is reported like individual window metrics, counts of used features, and individual function timings. Thermocouple A thermocouple , also known as a "thermoelectrical thermometer", is an electrical device consisting of two dissimilar electrical conductors forming an electrical junction . A thermocouple produces a temperature-dependent voltage as a result of the Seebeck effect , and this voltage can be interpreted to measure temperature . Thermocouples are widely used as temperature sensors . Commercial thermocouples are inexpensive, interchangeable, are supplied with standard connectors , and can measure

3420-430: Is sent through the drilling hole to the surface sensors and the demodulation software. The pressure wave (sana) is translated into useful information after DSP and noise filters. This information is used for Formation evaluation , Drilling Optimization, and Geosteering . Telemetry is a key factor in modern motor racing, allowing race engineers to interpret data collected during a test or race and use it to properly tune

3515-636: Is the primary source of real-time measurement and status information transmitted during the testing of crewed and uncrewed aircraft. Intercepted telemetry was an important source of intelligence for the United States and UK when Soviet missiles were tested; for this purpose, the United States operated a listening post in Iran . Eventually, the Russians discovered the United States intelligence-gathering network and encrypted their missile-test telemetry signals. Telemetry

3610-474: Is then either stored (with archival tags) or the tags can send (or transmit) their information to a satellite or handheld receiving device. Capturing and marking wild animals can put them at some risk, so it is important to minimize these impacts. At a 2005 workshop in Las Vegas , a seminar noted the introduction of telemetry equipment which would allow vending machines to communicate sales and inventory data to

3705-410: Is used by crewed or uncrewed spacecraft for data transmission. Distances of more than 10 billion kilometres have been covered, e.g., by Voyager 1 . In rocketry, telemetry equipment forms an integral part of the rocket range assets used to monitor the position and health of a launch vehicle to determine range safety flight termination criteria (Range purpose is for public safety). Problems include

3800-592: Is used by the railway industry for measuring the health of trackage . This permits optimized and focused predictive and preventative maintenance. Typically this is done with specialized trains, such as the New Measurement Train used in the United Kingdom by Network Rail , which can check for track defects, such as problems with gauge , and deformations in the rail. Japan uses similar, but quicker trains, nicknamed Doctor Yellow . Such trains, besides checking

3895-413: Is used for patients ( biotelemetry ) who are at risk of abnormal heart activity, generally in a coronary care unit . Telemetry specialists are sometimes used to monitor many patients within a hospital. Such patients are outfitted with measuring, recording and transmitting devices. A data log can be useful in diagnosis of the patient's condition by doctors . An alerting function can alert nurses if

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3990-576: Is used in many battery operated wireless systems to inform monitoring personnel when the battery power is reaching a low point and the end item needs fresh batteries. In the mining industry, telemetry serves two main purposes: the measurement of key parameters from mining equipment and the monitoring of safety practices. The information provided by the collection and analysis of key parameters allows for root-cause identification of inefficient operations, unsafe practices and incorrect equipment usage for maximizing productivity and safety. Further applications of

4085-830: Is used to communicate the variable measurements of flow and tank level sensors detecting fluid movements and/or volumes by pneumatic , hydrostatic , or differential pressure; tank-confined ultrasonic , radar or Doppler effect echoes; or mechanical or magnetic sensors. Telemetry of bulk solids is common for tracking and reporting the volume status and condition of grain and livestock feed bins, powdered or granular food, powders and pellets for manufacturing, sand and gravel, and other granular bulk solids. While technology associated with fluid tank monitoring also applies, in part, to granular bulk solids, reporting of overall container weight, or other gross characteristics and conditions, are sometimes required, owing to bulk solids' more complex and variable physical characteristics. Telemetry

4180-523: The European Space Agency (ESA), and other agencies use telemetry and/or telecommand systems to collect data from spacecraft and satellites. Telemetry is vital in the development of missiles, satellites and aircraft because the system might be destroyed during or after the test. Engineers need critical system parameters to analyze (and improve) the performance of the system. In the absence of telemetry, this data would often be unavailable. Telemetry

4275-456: The Seebeck coefficients of the conductors attached to the positive and negative terminals of the voltmeter, respectively (chromel and alumel in the figure). The thermocouple's behaviour is captured by a characteristic function E ( T ) {\displaystyle \scriptstyle E(T)} , which needs only to be consulted at two arguments: In terms of the Seebeck coefficients,

4370-454: The resistance thermometer (by William Siemens based on the work of Humphry Davy ), and the electrical strain gauge (based on Lord Kelvin 's discovery that conductors under mechanical strain change their resistance ) and output devices such as Samuel Morse 's telegraph sounder and the relay . In 1889 this led an author in the Institution of Civil Engineers proceedings to suggest that

4465-529: The 19th century. One of the first data-transmission circuits was developed in 1845 between the Russian Tsar 's Winter Palace and army headquarters. In 1874, French engineers built a system of weather and snow-depth sensors on Mont Blanc that transmitted real-time information to Paris . In 1901 the American inventor C. Michalke patented the selsyn , a circuit for sending synchronized rotation information over

4560-600: The European/German Type L is a variant of the type J, with a different specification for the EMF output (reference DIN 43712:1985-01 ). The positive wire is made of hard iron, while the negative wire consists of softer copper - nickel . Due to its iron content, the J-type is slightly heavier and the positive wire is magnetic. It is highly vulnerable to corrosion in reducing atmospheres, which can lead to significant degradation of

4655-510: The NASA launch complexes. [REDACTED]  This article incorporates public domain material from websites or documents of the National Aeronautics and Space Administration . Telemetry Telemetry is the in situ collection of measurements or other data at remote points and their automatic transmission to receiving equipment ( telecommunication ) for monitoring. The word

4750-475: The aged section of the thermocouple circuit is exposed to a temperature gradient, the measured voltage will differ, resulting in error. Aged thermocouples are only partly modified; for example, being unaffected in the parts outside the furnace. For this reason, aged thermocouples cannot be taken out of their installed location and recalibrated in a bath or test furnace to determine error. This also explains why error can sometimes be observed when an aged thermocouple

4845-446: The alloy, compensating for uncontrolled variations in source material. As a result, there are standard and specialized grades of thermocouple wire, depending on the level of precision demanded in the thermocouple behaviour. Precision grades may only be available in matched pairs, where one wire is modified to compensate for deficiencies in the other wire. A special case of thermocouple wire is known as "extension grade", designed to carry

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4940-412: The car for optimum performance. Systems used in series such as Formula One have become advanced to the point where the potential lap time of the car can be calculated, and this time is what the driver is expected to meet. Examples of measurements on a race car include accelerations ( G forces ) in three axes, temperature readings, wheel speed, and suspension displacement. In Formula One, driver input

5035-419: The characteristic function is defined by The constant of integration in this indefinite integral has no significance, but is conventionally chosen such that E ( 0 ∘ C ) = 0 {\displaystyle \scriptstyle E(0\,{}^{\circ }{\rm {C}})=0} . Thermocouple manufacturers and metrology standards organizations such as NIST provide tables of

5130-476: The chemical inertness of the thermocouple material and whether it is magnetic or not. Standard thermocouple types are listed below with the positive electrode (assuming T sense > T ref {\displaystyle T_{\text{sense}}>T_{\text{ref}}} ) first, followed by the negative electrode. Type E ( chromel – constantan ) has a high output (68 μV/°C), which makes it well suited to cryogenic use. Additionally, it

5225-425: The constituent metals, nickel , is magnetic; a characteristic of thermocouples made with magnetic material is that they undergo a deviation in output when the material reaches its Curie point , which occurs for type K thermocouples at around 185 °C. They operate very well in oxidizing atmospheres. If, however, a mostly reducing atmosphere (such as hydrogen with a small amount of oxygen) comes into contact with

5320-552: The crop. Monitoring stations usually transmit data back by terrestrial radio , although occasionally satellite systems are used. Solar power is often employed to make the station independent of the power grid. Telemetry is important in water management , including water quality and stream gauging functions. Major applications include AMR ( automatic meter reading ), groundwater monitoring, leak detection in distribution pipelines and equipment surveillance. Having data available in almost real time allows quick reactions to events in

5415-652: The dashboard which the team could update. Its development continued until May 2001, when it was first allowed on the cars. By 2002, teams were able to change engine mapping and deactivate engine sensors from the pit while the car was on the track. For the 2003 season, the FIA banned two-way telemetry from Formula One; however, the technology may be used in other types of racing or on road cars. One way telemetry system has also been applied in R/C racing car to get information by car's sensors like: engine RPM, voltage, temperatures, throttle. In

5510-710: The epilepsy monitoring unit, neuro ICU, pediatric ICU and newborn ICU. Due to the labor-intensive nature of continuous EEG monitoring NT is typically done in the larger academic teaching hospitals using in-house programs that include R.EEG Technologists, IT support staff, neurologist and neurophysiologist and monitoring support personnel. Modern microprocessor speeds, software algorithms and video data compression allow hospitals to centrally record and monitor continuous digital EEGs of multiple critically ill patients simultaneously. Neurotelemetry and continuous EEG monitoring provides dynamic information about brain function that permits early detection of changes in neurologic status, which

5605-478: The extreme environment (temperature, acceleration and vibration), the energy supply , antenna alignment and (at long distances, e.g., in spaceflight ) signal travel time . Today nearly every type of aircraft , missiles , or spacecraft carries a wireless telemetry system as it is tested. Aeronautical mobile telemetry is used for the safety of the pilots and persons on the ground during flight tests. Telemetry from an on-board flight test instrumentation system

5700-516: The field. Telemetry control allows engineers to intervene with assets such as pumps and by remotely switching pumps on or off depending on the circumstances. Watershed telemetry is an excellent strategy of how to implement a water management system. Telemetry is used in complex systems such as missiles, RPVs, spacecraft , oil rigs , and chemical plants since it allows the automatic monitoring, alerting, and record-keeping necessary for efficient and safe operation. Space agencies such as NASA , ISRO ,

5795-419: The function E ( T ) {\displaystyle \scriptstyle E(T)} that have been measured and interpolated over a range of temperatures, for particular thermocouple types (see External links section for access to these tables). To obtain the desired measurement of T s e n s e {\displaystyle \scriptstyle T_{\mathrm {sense} }} , it

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5890-566: The furnace causes the temperature gradient to occur only in a fresh section. Certain combinations of alloys have become popular as industry standards. Selection of the combination is driven by cost, availability, convenience, melting point, chemical properties, stability, and output. Different types are best suited for different applications. They are usually selected on the basis of the temperature range and sensitivity needed. Thermocouples with low sensitivities (B, R, and S types) have correspondingly lower resolutions. Other selection criteria include

5985-516: The instrumentation power systems were grounded separately. Fluorescent lights, a source of electromagnetic interference, were not permitted. Its architect, Charles Luckman , also designed other nearby buildings. A smaller building, later known as the CIF antenna site, was placed 1.5 miles (2.5 km) north of the Industrial Area, to be free of radio-frequency interference and have clear line-of-sight to

6080-746: The introduction of the International Temperature Scale of 1990 (ITS-90), precision type-S thermocouples were used as the practical standard thermometers for the range of 630 °C to 1064 °C, based on an interpolation between the freezing points of antimony , silver , and gold . Starting with ITS-90, platinum resistance thermometers have taken over this range as standard thermometers. These thermocouples are well-suited for measuring extremely high temperatures. Typical uses are hydrogen and inert atmospheres, as well as vacuum furnaces . They are not used in oxidizing environments at high temperatures because of embrittlement . A typical range

6175-589: The item, its package, or (for large items and bulk shipments) affixed to its shipping container or vehicle. This facilitates knowledge of their location, and can record their status and disposition, as when merchandise with barcode labels is scanned through a checkout reader at point-of-sale systems in a retail store. Stationary or hand-held barcode RFID scanners or Optical reader with remote communications, can be used to expedite inventory tracking and counting in stores, warehouses, shipping terminals, transportation carriers and factories. Fluids stored in tanks are

6270-572: The late 1940s used either PPM (e.g., the Tral telemetry system developed by OKB-MEI) or pulse-duration modulation (e.g., the RTS-5 system developed by NII-885). In the United States, early work employed similar systems, but were later replaced by pulse-code modulation (PCM) (for example, in the Mars probe Mariner 4 ). Later Soviet interplanetary probes used redundant radio systems, transmitting telemetry by PCM on

6365-465: The left, the reference junction in the middle and represents the rest of the electrical system as a voltage meter on the right. The temperature T sense is obtained via a characteristic function E ( T ) for the type of thermocouple which requires inputs: measured voltage V and reference junction temperature T ref . The solution to the equation E ( T sense ) = V + E ( T ref ) yields T sense . Sometimes these details are hidden inside

6460-476: The low cost and ubiquity of GSM networks by using SMS to receive and transmit telemetry data. A telemeter is a physical device used in telemetry. It consists of a sensor , a transmission path, and a display, recording, or control device. Electronic devices are widely used in telemetry and can be wireless or hard-wired, analog or digital . Other technologies are also possible, such as mechanical, hydraulic and optical. Telemetry may be commutated to allow

6555-716: The most efficient use of energy. Such systems also facilitate predictive maintenance . Many resources need to be distributed over wide areas. Telemetry is useful in these cases, since it allows the logistics system to channel resources where they are needed, as well as provide security for those assets; principal examples of this are dry goods, fluids, and granular bulk solids. Dry goods, such as packaged merchandise, may be tracked and remotely monitored, tracked and inventoried by RFID sensing systems, barcode reader , optical character recognition (OCR) reader, or other sensing devices—coupled to telemetry devices, to detect RFID tags , barcode labels or other identifying markers affixed to

6650-588: The most stable thermocouples, but have lower sensitivity than other types, approximately 10 μV/°C. Type B, R, and S thermocouples are usually used only for high-temperature measurements due to their high cost and low sensitivity. For type R and S thermocouples, HTX platinum wire can be used in place of the pure platinum leg to strengthen the thermocouple and prevent failures from grain growth that can occur in high temperature and harsh conditions. Type B (70%Pt/30%Rh–94%Pt/6%Rh, by weight) thermocouples are suited for use at up to 1800 °C. Type-B thermocouples produce

6745-430: The patient is suffering from an acute (or dangerous) condition. Systems are available in medical-surgical nursing for monitoring to rule out a heart condition, or to monitor a response to antiarrhythmic medications such as amiodarone . A new and emerging application for telemetry is in the field of neurophysiology, or neurotelemetry. Neurophysiology is the study of the central and peripheral nervous systems through

6840-415: The presence of sulfur. Type T ( copper – constantan ) thermocouples are suited for measurements in the −200 to 350 °C range. Often used as a differential measurement, since only copper wire touches the probes. Since both conductors are non-magnetic, there is no Curie point and thus no abrupt change in characteristics. Type-T thermocouples have a sensitivity of about 43 μV/°C. Note that copper has

6935-469: The recording of bioelectrical activity, whether spontaneous or stimulated. In neurotelemetry (NT) the electroencephalogram (EEG) of a patient is monitored remotely by a registered EEG technologist using advanced communication software. The goal of neurotelemetry is to recognize a decline in a patient's condition before physical signs and symptoms are present. Neurotelemetry is synonymous with real-time continuous video EEG monitoring and has application in

7030-679: The same output at 0 °C and 42 °C, limiting their use below about 50 °C. The emf function has a minimum around 21 °C (for 21.020262 °C emf=-2.584972 μV), meaning that cold-junction compensation is easily performed, since the compensation voltage is essentially a constant for a reference at typical room temperatures. Type R (87%Pt/13%Rh–Pt, by weight) thermocouples are used 0 to 1600 °C. Type R Thermocouples are quite stable and capable of long operating life when used in clean, favorable conditions. When used above 1100 °C ( 2000 °F), these thermocouples must be protected from exposure to metallic and non-metallic vapors. Type R

7125-537: The same temperature change and an identical material. As a result, T m e t e r {\displaystyle \scriptstyle T_{\mathrm {meter} }} does not influence the measured voltage. The second and third contributions do not cancel, as they involve different materials. The measured voltage turns out to be where S + {\displaystyle \scriptstyle S_{+}} and S − {\displaystyle \scriptstyle S_{-}} are

7220-415: The technology allow for sharing knowledge and best practices across the organization. In software, telemetry is used to gather data on the use and performance of applications and application components, e.g. how often certain features are used, measurements of start-up time and processing time, hardware, application crashes, and general usage statistics and/or user behavior. In some cases, very detailed data

7315-426: The telemetry equipment reports the location of the vehicle, enabling law enforcement to deactivate the engine and lock the doors when it is stopped by responding officers. In some countries, telemetry is used to measure the amount of electrical energy consumed. The electricity meter communicates with a concentrator , and the latter sends the information through GPRS or GSM to the energy provider's server. Telemetry

7410-564: The telemetry from Soviet missile tests by building a telemeter of their own to intercept the radio signals and hence learn a great deal about Soviet capabilities. Telemeters are the physical devices used in telemetry. It consists of a sensor , a transmission path, and a display, recording, or control device. Electronic devices are widely used in telemetry and can be wireless or hard-wired, analog or digital . Other technologies are also possible, such as mechanical, hydraulic and optical. Telemetering information over wire had its origins in

7505-612: The temperature measurement. For the simplest measurements, thermocouple wires are connected to copper far away from the hot or cold point whose temperature is measured; this reference junction is then assumed to be at room temperature, but that temperature can vary. Because of the nonlinearity in the thermocouple voltage curve, the errors in T r e f {\displaystyle T_{\mathrm {ref} }} and T s e n s e {\displaystyle T_{\mathrm {sense} }} are generally unequal values. Some thermocouples, such as Type B, have

7600-479: The temperature sensors in thermostats , and also as flame sensors in safety devices for gas-powered appliances. In 1821, the German physicist Thomas Johann Seebeck discovered that a magnetic needle held near a circuit made up of two dissimilar metals got deflected when one of the dissimilar metal junctions was heated. At the time, Seebeck referred to this consequence as thermo-magnetism. The magnetic field he observed

7695-472: The term for the rangefinder telemeter might be replaced with tacheometer . In the 1930s use of electrical telemeters grew rapidly. The electrical strain gauge was widely used in rocket and aviation research and the radiosonde was invented for meteorological measurements. The advent of World War II gave an impetus to industrial development and henceforth many of these telemeters became commercially viable. Carrying on from rocket research, radio telemetry

7790-464: The thermocouple's performance. Type K ( chromel – alumel ) is the most common general-purpose thermocouple with a sensitivity of approximately 41 μV/°C. It is inexpensive, and a wide variety of probes are available in its −200 °C to +1350 °C (−330 °F to +2460 °F) range. Type K was specified at a time when metallurgy was less advanced than it is today, and consequently characteristics may vary considerably between samples. One of

7885-473: The thermoelectric circuit over a longer distance. Extension wires follow the stated E ( T ) {\displaystyle \scriptstyle E(T)} curve but for various reasons they are not designed to be used in extreme environments and so they cannot be used at the sensing junction in some applications. For example, an extension wire may be in a different form, such as highly flexible with stranded construction and plastic insulation, or be part of

7980-485: The three principal characteristic types and causes of thermoelectric instability in the standard base-metal thermoelement materials: The Nicrosil and Nisil thermocouple alloys show greatly enhanced thermoelectric stability relative to the other standard base-metal thermocouple alloys because their compositions substantially reduce the thermoelectric instabilities described above. This is achieved primarily by increasing component solute concentrations (chromium and silicon) in

8075-590: The tracks, can also verify whether or not there are any problems with the overhead power supply (catenary), where it is installed. Dedicated rail inspection companies, such as Sperry Rail , have their own customized rail cars and rail-wheel equipped trucks, that use a variety of methods, including lasers, ultrasound, and induction (measuring resulting magnetic fields from running electricity into rails) to find any defects. Most activities related to healthy crops and good yields depend on timely availability of weather and soil data. Therefore, wireless weather stations play

8170-410: The transmission of multiple data streams in a fixed frame . The beginning of industrial telemetry lies in the steam age , although the sensor was not called telemeter at that time. Examples are James Watt 's (1736-1819) additions to his steam engines for monitoring from a (near) distance such as the mercury pressure gauge and the fly-ball governor . Although the original telemeter referred to

8265-430: The transportation industry, telemetry provides meaningful information about a vehicle or driver's performance by collecting data from sensors within the vehicle. This is undertaken for various reasons ranging from staff compliance monitoring, insurance rating to predictive maintenance. Telemetry is used to link traffic counter devices to data recorders to measure traffic flows and vehicle lengths and weights. Telemetry

8360-440: The voltmeter itself. If the thermocouple wire has a high resistance for some reason (poor contact at junctions, or very thin wires used for fast thermal response), the measuring instrument should have high input impedance to prevent an offset in the measured voltage. A useful feature in thermocouple instrumentation will simultaneously measure resistance and detect faulty connections in the wiring or at thermocouple junctions. While

8455-497: The wires in a thermocouple that is used to measure very high temperatures may change with time, and the measurement voltage accordingly drops. The simple relationship between the temperature difference of the junctions and the measurement voltage is only correct if each wire is homogeneous (uniform in composition). As thermocouples age in a process, their conductors can lose homogeneity due to chemical and metallurgical changes caused by extreme or prolonged exposure to high temperatures. If

8550-413: The wires, the chromium in the chromel alloy oxidizes. This reduces the emf output, and the thermocouple reads low. This phenomenon is known as green rot , due to the color of the affected alloy. Although not always distinctively green, the chromel wire will develop a mottled silvery skin and become magnetic. An easy way to check for this problem is to see whether the two wires are magnetic (normally, chromel

8645-509: Was also a source for the Soviets, who operated listening ships in Cardigan Bay to eavesdrop on UK missile tests performed in the area . In factories, buildings and houses, energy consumption of systems such as HVAC are monitored at multiple locations; related parameters (e.g., temperature) are sent via wireless telemetry to a central location. The information is collected and processed, enabling

8740-467: Was based on systems developed during Saturn I operations at Complexes 34 and 37, such experience was of limited value, because the distance from Launch Complex 39 to its Launch Control Center was more than 14 times as long. Planning and construction were coordinated with other NASA centers and with the Atlantic Missile Range . All metal in the building was grounded, and commercial power and

8835-482: Was later shown to be due to thermo-electric current. In practical use, the voltage generated at a single junction of two different types of wire is what is of interest as this can be used to measure temperature at very high and low temperatures. The magnitude of the voltage depends on the types of wire being used. Generally, the voltage is in the microvolt range and care must be taken to obtain a usable measurement. Although very little current flows, power can be generated by

8930-574: Was left dormant during the intermediate part of the space shuttle program (as other facilities such as the launch control center managed most of the instrumentation in the 2000s), and fell into disrepair. In September 2017, all the equipment inside was donated to the visitor complex and storage facilities, while the disused building was eventually demolished in October. The CIF reflected the desire of Karl Sendler, KSC's first director of information systems, and his planners to centralize data handling. Although it

9025-534: Was used routinely as space exploration got underway. Spacecraft are in a place where a physical connection is not possible, leaving radio or other electromagnetic waves (such as infrared lasers) as the only viable option for telemetry. During crewed space missions it is used to monitor not only parameters of the vehicle, but also the health and life support of the astronauts. During the Cold War telemetry found uses in espionage. US intelligence found that they could monitor

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