Thermal converter of resistances: the description of blasts and their error

The thermocouple is a device that is designed to measure temperature. The principle of operation of this device is based on the electrical resistance of metals and individual alloys. Semiconductors are considered to be the main element of thermocouples. Some experts call them thermistors.

If we consider a standard thermocouple, then there is only one resistor in it. It is made entirely of metal wire. In some cases, it can be made from a film. To date, platinum thermal converters are considered to be the most common. This is due to the fact that this metal has a good resistance to temperature. Also, platinum is more resistant to oxidation. Reproducibility thermocouples of this type show quite high.

Modern models are made of high purity platinum. In this case, the temperature coefficient of the metal is at the level of 0.003. However, there are many copper and nickel devices on the market. All technical requirements are dictated by GOST. In frequency, this system of measurement uniformity results in temperature ranges, accuracy classes and standard resistance dependencies.

Two-wire modifications

For working in a gaseous medium a two-wire thermal resistance transducer is used. The scheme of its arrangement is quite simple. In the upper part is a sensor with a conductor. He connects with the union. In the lower part of the case there are clamps and cable. The error at minus temperatures for models does not exceed 0.3 degrees.

Tolerance according to GOST 6651 the specified modifications have a series A. If we consider the thermal resistance transducer PT100, then the minimum temperature parameter of the device lies in the region of -60 degrees. If we talk about the design features of models, it is important to note that they are produced with a sealant. Conclusions, as a rule, there are two. Directly clamps are installed in the front of the case.

Three-wire thermal converters

A three-wire thermal resistance converter is excellent for a liquid medium. However, the minimum temperature parameter for the models is, on average, -30 degrees. It is also important to note that the error in an aggressive environment can reach up to 0.45 degrees. There are two pins in devices of this type. Direct admission to GOST 6651 is available in series A. The minimum permissible temperature is around 230 degrees.

If we consider the thermal resistance transducer TC 1088, then the length of its mounting part reaches 100 mm. If we talk about modifications with a terminal head, then they have three outputs. The protective armature is used with the 12Х marking. The indicator of thermal inertia can reach up to 10 s. In turn, the maximum conditional pressure parameter is equal to an average of 6.2 Py. Verification of thermal resistance transducers is performed using temperature calibrators.

Four-wire devices

Four-wire thermal resistance transducer is designed for temperature measurements in a liquid medium. If we talk about the error of resistance, then this parameter can reach 0.03 Ohm. In this case, the sensitivity of the instruments is on average 33 microns. If we talk about modifications with tolerance A, then the minimum temperature at which they are able to work is 30 degrees below zero. The nominal static characteristic of the devices is up to 100 MP. The protective armature in many modifications is used with the 12Х marking.

If we consider the thermal resistance transducer DTS 105, then the maximum temperature is 230 degrees. The tolerable deviation limit is no more than 0.15 T. It is also important to note that devices of this type are available with terminal heads. The insulation in them is only ceramic. In this case, the clips are installed in the front of the case. If we talk about sensitivity, then these devices have a maximum of 32 microns.

Platinum modifications

Platinum thermal resistance transducer (KTSP) boasts an excellent indicator of thermal inertia. However, in this case it is important to take into account the model's admission in accordance with GOST 6651. If we consider the modifications of the A series, then in this situation the nominal static characteristic of the devices does not exceed 50 P. The parameter of thermal inertia in turn equals 10 s.

The maximum temperature of the thermal resistance transducer (platinum) series A is capable of carrying 240 degrees. Protective armatures for models are most often used with the 12Х marking. If we consider the thermal resistance converter (GOST 6651) with the B series tolerance, then the parameter of the nominal static characteristic is 100 P. The thermal inertia exponent in its turn reaches 25 s.

Copper devices and their parameters

The resistance thermocouple (copper) is suitable only for gaseous media. By the parameter of the error, the modifications are quite different. First of all, it is necessary to consider thermocouples with a tolerance of series A. They are used at a temperature of even -50 degrees. However, their sensitivity is not too good. On average, this parameter does not exceed 34 microns. All this suggests that at a temperature of less than 0 degrees, the error is on average 0.5 degrees.

The indicator of thermal inertia in turn reaches 10 seconds. In this case, the maximum possible temperature for the models is 230 degrees. The tolerable limit of deviations in this case reaches 0.12 T. If we talk about design features, there are no terminal heads for models of this type. The sealant is used in many configurations with powder. Directly insulators are often of a silicon type. If we consider thermal converters with a B-series tolerance, then they have a sensitivity of 40 microns. All this suggests that at temperatures below 0 degrees the error can reach 0.45 degrees.

Considering the design features of the modifications, it is important to note that many models are equipped with terminal boxes. In this case, the sealant is usually applied with a powder. Directly clamps are installed in the front of the case. The protective armature is most often used with the marking 15X.

Nickel devices

The nickel resistance thermocouple is currently in high demand. First of all, this is due to the fact that the models have a high parameter of tolerated deviations. Also, many modifications can boast excellent conductivity. If we consider devices with a tolerance in accordance with GOST 6651 series A, then it is important to mention that the error parameter does not exceed 0.23 degrees. The allowable deviation limit in turn is at 0.12 T.

The nominal static characteristic of the models is on the average 30P. However, it is also important to consider modifications with access to the B series. They have protected enclosures, and they can withstand a maximum temperature of 230 degrees. The length of the mounting part of the models does not exceed 100 mm on the average. If we talk about the basic parameters, it is important to mention that the sensitivity of the instruments on average is 35 microns. The maximum conditional pressure of the system is maintained at 6.6 Py. The parameter of thermal inertia never exceeds 13 s.

High-temperature models

High-temperature thermal resistance transducer can be manufactured with different tolerances. Depending on it, the error parameter, and other parameters of the device will change. If to speak about access of a series And, thermal converters of the given type have high conditional pressure. Minimum devices can be used at a temperature of -30 degrees. The housings of these devices are well protected from dust. The permissible error of the instrument does not exceed 0.12 T. The sensitivity in turn is 33 microns.

The nominal static characteristic of thermal converters is 40 V. However, it is also important to consider modifications with access to the B series. According to GOST 6651, the sensitivity index must be at least equal to 20 microns. At temperatures above 0 degrees, the error rate of the instruments does not exceed 0.44 degrees.

If we talk about the design features of the models, the clamps at them are installed in the front part of the case. Directly the head is located at the top of the device. There are two conclusions. It is also important to mention that thermocouples of this type are equipped with ceramic thermal insulation.

Features of submersible modifications

The immersion thermocouple is necessarily equipped with a terminal box. Cable cores in many models are hidden with a sheath. Clamps in this case are located in the lower part of the body. Directly the parameters of the product are closely related to the access series in accordance with GOST 6651. However, it should be noted at once that the immersion thermocouple can be used in aggressive environments. If we consider modifications with a tolerance of series A, then the sensitivity of the instrument in this case does not exceed 42 microns. The error is 0.02 degrees. However, it is important to take into account that the indicator of thermal inertia will never exceed 10 s.

The nominal static characteristic of submersible devices is 50 P according to GOST 6651. There are two conclusions in the presented thermocouples. It is also important to consider models with access to the B series. First of all, a high sensitivity parameter deserves attention - at a level of 30 microns. All this makes it possible to reduce the error of the instrument to 0.023 degrees. The maximum temperature of the medium in this case should not exceed 240 degrees. The length of the mounting part of the models is 85 mm on the average. Directly protective valves are used with the 12Х marking. The index of thermal inertia in thermocouples does not exceed 3 s.

Explosion-proof versions

The thermal converter of this type is designed to work in a gaseous medium. In this case, the terminal heads are used with the union. Maximum temperature devices are able to withstand at 250 degrees. The indicator of thermal inertia is closely related to the device access series. However, it is important to note that all models have a maximum conditional pressure of 6.7 Py. If we consider devices with series A access, then it is important to mention that the error at a temperature above 0 degrees equals 0.035 degrees.

The terminal head in these configurations is installed at the top of the housing. The directly nominal static characteristic of thermal converters does not exceed 60 P. The permissible deviation limit of the device is on the average 0.20 T. It is also important to consider thermal converters with access to the B series. There are three leads. Directly the insulation is of a ceramic type. As stated before, the maximum conditional pressure is maintained at 6.7 Py. Minimum models can be operated at a temperature of -30 degrees.

The sensitivity of the devices does not exceed 40 microns. The error at temperatures above 0 degrees is approximately 0.040 degrees. The nominal static characteristic of the devices is 40 P. The mounting part of the models does not exceed 80 mm. The parameter of thermal inertia in the devices is quite high. However, the allowed deviation limit is only 0.33 T.

Accuracy TSP-0196-01

Thermal transducer TSP 0196-01 is designed for liquid media. According to GOST 6651, it has the B series tolerance. The minimum ambient temperature is -35 degrees. The nominal static characteristic of the device does not exceed 50 P. If we consider modifications with terminal boxes, then the length of the mounting part is 85 mm. The protective armature of the model is applied with the marking 13X. The indicator of thermal inertia of the device is at the level of 15 s. In turn, the maximum temperature is 240 degrees.

The tolerable limit of deviations on the average does not exceed 0.15 T. At temperatures above 0 degrees, the thermal resistance transducer TSP 0196-01 gives an error of 0.033 degrees. The configuration with the terminal boxes is equipped with three terminals. In this case, the sensor is located in the front of the housing. Direct insulation is provided by the manufacturer of the ceramic type. The sealant in turn is applied with the powder. Thus, the case is quite strongly protected, and with the oxidation of metal in this model, problems are rare.

Model ТСМ-0196-02

Thermal converter TCM 0196-02 is designed to work in a liquid environment. It has good conductivity, and a high maximum temperature parameter. However, in the first place, it should be noted that the tolerance in accordance with GOST 6651 it has a series A. In this case, the minimum temperature is -50 degrees.

For laboratory studies, the specimen is often used. At temperatures above 0 degrees, its error is no more than 0.045 degrees. The nominal static characteristic of the device is about 55 P. The mounting part of this model is 85 mm. Directly protected valves are used with the 12X marking.

The maximum temperature is at 250 degrees. The terminal box is not in the specified configuration. The manufacturer provides two conclusions. Problems with the oxidation of the metal arise quite rarely, since the sealing is used with the powder. Isolation in this case is reliable.

Thermocouple TSP-0196-06

A thermocouple of this type is quite in demand in the production of fusible metals. In this case, the protective armature is provided by 15X. Direct admission according to GOST 6651 model has series B. The minimum ambient temperature is -30 degrees. A high sensitivity parameter deserves special attention. However, it should be noted that at temperatures above 0 degrees, the error of the thermal converter is 0.022 degrees.

The length of the mounting part of the model is only 60 mm. The indicator of thermal inertia is at the level of 12 seconds. The maximum permissible ambient temperature at which the device can be used is 240 degrees. The terminal head for this thermocouple is provided.