In industry and many other areas, temperature sensors are often used. They are considered to be one of the most important elements in the system. There are many types of such equipment. PT100 is a temperature sensor that is currently quite common. This line also includes such models as PT500, PT1000. The numbers in the designation indicate the resistance of this type of temperature meters.
General Description
Due 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 temperature sensor PT100, then it belongs to platinum. In addition, it is one of the most popular devices. This is mainly due to the good price-quality ratio. Another convenience is the ability to use the device as an independent device, as well as the ability to be built into the sleeve of another device to record temperature data. Naturally, in this case, one should take into account the diameter of the PT100 temperature sensor and the sleeve of the device where it will be needed.insert to avoid misunderstandings during installation. The two most common industries using this thermal sensor are thermal power and ventilation systems.
Working principle
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 Ohm. Since platinum has a positive coefficient, with an increase in temperature, its resistance will also increase. Up to three thermal resistances can be built into one device, however, today the most popular is the device with one element.
Another characteristic of the PT100 temperature sensor is the ability to connect via a two-, three-, four-wire method. This parameter will depend on the type of circuit in which the temperature 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 a medium such as liquid or gas.
Short list of characteristics
This temperature sensor is approved for use in an environment where the maximum temperature will not exceed 350°C. For a short period of time, it can be placed in an environment with indicators of 400 ° C. In terms of compatibility, the PT100 RTD temperature sensor can be used with any device that has a resistance similar to that of this equipment.
More importantNote that these parameters are averages. Depending on the manufacturer of this device, all indicators may vary somewhat 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 indicators of +600 ° С.
Accurate device specifications
The characteristic diagram of the PT100 temperature sensor can be quite well disassembled using the example of an industrial thermostat, for example:
- The body of the instrument is usually made of stainless steel;
- weight 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 sensing element of the device;
- working temperature range of this particular model is from -50 °С to +80 °С;
- as for the possible temperature measurement range, it is somewhat larger: from -50 degrees to +100 degrees Celsius;
- Equipment measurement error is very low - 2%;
- during operation, the power consumption of the device is 2W;
- at 35 °C 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 strictly not recommended:
- high level placesvibration;
- in places with a high probability of damage to the body of the device;
- in aggressive chemical environments;
- where there is a high risk of explosion;
- near sources of electrical interference.
During installation, it is also important to follow exactly all the instructions in the installation instructions, and then follow exactly the instructions for use.
Siemens and Moni model specifications
The price of the PT100 temperature sensor from Raychem, model moni-exe, for example, is about 40 thousand rubles. Two more popular models should be considered. The first one 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 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 °С to +130 °С.
- Equipment dimensions 80 x 60 x 31 mm.
- The material used for the manufacture of the immersion part of the device is stainless steel.
As for the moni-exe PT100 temperature sensor, its characteristics are as follows:
- 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;
- maximumallowable tip temperature +585 °С.
Instrument operation
As mentioned earlier, the principle of operation is based on the operation of the platinum element of the sensor, which has 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 - positive, that is, with increasing temperature, the resistance also increases, for negative ones, the opposite is true.
A feature of these devices is the ability to measure three temperature media simultaneously, with 3 resistance sensors in one box. However, this assembly was not very efficient, and therefore only single-element devices are mainly used.
Measurement accuracy during equipment operation 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 functioning of the device is the division into accuracy classes A and B. The second type, in turn, is divided into two more 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 instruments.
Device installation work
It should be said right away that before starting any work related to installation, you should carefully read the instructions. Only thosepersons who have read all the papers.
This device is installed directly at the measurement site. To fasten it, use a wrench that is 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 start connecting the electrical cables of the sensor according to its diagram, which is usually included in the kit. 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 about the operation of this device emphasize its convenience. It is very easy to use the sensor, installation also does not cause problems. It does its job very well. Of the shortcomings, it should be noted that it quickly fails if the operating rules are not followed or it is poorly attached to the measurement site. Some relay elements may also fail.
In order to avoid all these problems, users are strongly advised to read the installation and operating instructions very carefully. Only after that start any work. The characteristic diagram 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.
