In industry and many other areas, temperature sensors are often used. They are considered one of the most important elements in the system. There are many types of similar equipment. PT100 is a temperature sensor, which is currently quite common. This range also includes models such as PT500, PT1000. The numbers in the designation indicate the resistance of temperature meters of this type.
general description
Thanks to the development of technology, several different types of temperature sensors have appeared. They can be platinum, nickel, copper and others. If we talk about the PT100 temperature sensor, then it refers to platinum. In addition, it is one of the most popular devices. Basically, this is the merit of a good price-quality ratio. Another convenience is the ability to use the device as a stand-alone device, as well as the ability to integrate into the sleeve of another device for recording temperature data. Naturally, in this case, you should take into account the diameter of the PT100 temperature sensor and the sleeve of the device, where it will need to be inserted in order to avoid misunderstandings during installation. The two most common industries using this thermal sensor are heat and ventilation systems.
Principle of operation
The principle of operation of the PT100 temperature sensor is based on the fact that at zero temperature the resistance of its platinum elements is 100 Ohms. Since platinum has a positive coefficient, then with increasing temperature, its resistance will increase. Up to three thermal resistances can be integrated in one device, but today the device with one element is the most popular.
Another characteristic of the PT100 temperature sensor is the ability to connect via two-, three-, and four-wire methods. This parameter will depend on the type of circuit in which the thermal sensor is installed. In addition, the purpose and location of the equipment will play an important role here. The PT100 platinum temperature sensor is designed to measure the temperature of an environment such as liquid or gas.
Short list of features
This temperature measurement sensor may be used in an environment where the maximum temperature regime will not exceed 350 ° C. For a short period of time it can be placed in an environment with indicators of 400 ° C. As for compatibility, the PT100 temperature sensor PT100 can be used with any device with a resistance similar to that of this equipment.
Further, it is important to note that these parameters are averaged. Depending on the manufacturer of this device, all indicators may vary slightly in either direction. The choice of a particular device with specific characteristics depends entirely on the purposes for which the owner plans to use it. There are devices that can function normally in an environment with +600 ° indicators.
Accurate instrument specifications
The diagram of the characteristics of the PT100 temperature sensor can be quite well disassembled using the example of an industrial thermal relay, for example:
- the case of the device is usually made of stainless steel;
- weight is approximately 600 grams;
- the dimensions of the device are 62 x 66 x 67 cm, and they do not take into account the dimensions of the sensitive element of the device;
- the operating temperature range of this particular model is from -50 ° C to +80 ° C;
- as for the possible range of temperature measurement, it is slightly larger: from -50 degrees to +100 degrees Celsius;
- the measurement error of the equipment is very low - 2%;
- during operation, the power consumption of the device is 2 W;
- at 35 ° humidity should be about 80% and no more;
- the last indicator is the working pressure, which can be 0.01 or 1.6 MPa.
There are several conditions under which the installation of this equipment is not strictly recommended:
- places with a high level of vibration;
- in places with a high probability of damage to the device body;
- in aggressive chemical environments;
- in places with a high level of explosion hazard;
- close to electrical noise sources.
During installation, it is also important to follow all the instructions in the installation instructions exactly, and then follow exactly the operating recommendations.
Siemens and Moni model specifications
The price of a PT100 temperature sensor from Raychem moni-exe model, for example, is about 40 thousand rubles. The characteristics of two more popular models should be considered. The first of them is Siemens QAE2111.015:
- This device is used to measure the return temperature in an air conditioning or heating system. In other words, the device will help to control the temperature of the incoming and returning coolant in the system.
- This type of sensor belongs to the submersible PT100 category.
- The temperature measurement range is from -30 ° C to +130 ° C.
- The dimensions of the equipment are 80 x 60 x 31 mm.
- The material used to make the immersion part of the device is stainless steel.
As for the moni-exe PT100 temperature sensor, its characteristics are as follows:
- the measurement range is much wider - from -100 to +500 degrees Celsius;
- device dimensions - 80 x 75 x 55 mm;
- this equipment can be operated at temperatures from -50 ° C to +60 ° C;
- maximum permissible tip temperature +585 ° .
Device operation
As mentioned earlier, the principle of operation is based on the operation of the platinum element of the sensor having a resistance of 100 Ohms at 0 degrees, respectively, its resistance will be 1000 Ohms at 100 degrees, etc. When self-diagnosing or buying such devices, it is important to know that there are devices with a positive and negative coefficient. Platinum PT100 is positive, that is, with increasing temperature, resistance also grows, while for negative ones the opposite is true.
A feature of these devices is the ability to measure three temperature environments at the same time, with 3 resistance sensors in one box. However, such an assembly was not very effective, and therefore basically only devices with one element are used.
The accuracy of measurements during operation of the equipment depends on the number of wires used for connection. They can be from 2 to 4 pieces.
Another classification that plays an important role in the operation of the device is the division into accuracy classes A and B. The second type, in turn, is divided into two subgroups - these are B 1/3 DIN and B 1/10 DIN. Their main difference from other types of PT100 sensors is that they cannot be used as stand-alone devices.
Installation work
Immediately it is worth saying that before starting any work related to installation, you should carefully read the instructions. Direct work is allowed only to those who have read all the papers.
This device is installed directly at the measurement site. To fix it, use a wrench suitable in size for the hexagon of the device. You will need to create a good seal, for which you can use mastic, tow, sealing tape and other devices. After that, you can proceed to connect the electric cables of the sensor according to its scheme, which is usually included. It is important to note here that the working position of the sensor is arbitrary, this allows it to be installed in any convenient place.
Device Reviews
Reviews on the operation of this device emphasize its convenience. It is very simple to use the sensor; installation also does not cause problems. It copes with its functions perfectly. Of the shortcomings, it should be noted that it quickly fails if you do not follow the operating rules or are poorly attached to the measurement site. Some relay elements may also fail.
In order to avoid all these problems, users strongly recommend that you read the installation and operating instructions very carefully. Only after that proceed with any work. The diagram of the characteristics of the PT100 temperature sensor, the resistance of this device (100 Ohms at 0 degrees Celsius) and other important parameters helped it to firmly establish itself in the sales market.