Selection of common transmitters.

Pressure transmitter with its simple structure, strong and durable. High stability and high precision and good linear characteristic, using cutting has a wide measuring range and are widely used in various industrial control environment, involved in water conservancy and hydropower, railway transportation, intelligent buildings, production control, aerospace, military industry, petrochemical, oil, electric power, ships, machine tools, pipe, and many other industries, this article introduces some common used in the selection of transducer

Selection of transmitter.

The selection of the transmitter should mainly consider the range of pressure range, pressure medium, precision grade, temperature range, signal output, excitation voltage, interchangeability, explosion protection and protection grade.

1. Range of pressure range:

In order to confirm the maximum value of the measurement pressure, it is usually necessary to select a transmitter with a pressure range of about 1.5 times larger than the maximum. Therefore, in selecting the transmitter, the pressure range, precision and stability should be considered.

2. Pressure media:

We want to consider is the measured medium pressure transmitter, viscous liquid, the mud will be blocked pressure interface, solvents or corrosive substances will destroy transmitting Lv Zhong direct contact with the medium materials. The above factors will determine whether to choose direct isolation film and direct contact with media. The average pressure transmitter in contact with the medium part adopts 316 stainless steel, if you're not corrosive medium of 316 stainless steel, so basically all the pressure transmitter of medium pressure measurement is fit for you. If you have a corrosive medium of 316 stainless steel, so we're going to use chemical seal, such not only can measure the medium pressure, and can effectively prevent the medium liquid part of the contact with the contact of the pressure transmitter, thus protect pressure transmitter, prolong the service life of pressure transmitter.

3. Accuracy grade:

The determinations of precision are nonlinearity, hysteresis, non-repeatability of electromechanical business network, temperature, zero offset scale, and temperature influence. But mainly by non-linear, hysteresis, non-repeatability, the higher the precision, the higher the price.

4. Temperature range:

A transmitter typically calibrates two temperature ranges, which is the range of temperature and the range of compensation for normal operation.

The normal operating temperature range refers to the temperature range when the transmitter is not destroyed in the working state, and may not reach the performance index of its application when the temperature is exceeded.

The temperature compensation range is a typical range smaller than the operating temperature range. In this range, the transmitter is sure to meet its due performance targets. Temperature change affects its output from two aspects, one is zero drift; The second is to affect the full range output. Such as: full range of + / - X % / ℃, readings of + / - X % / ℃, in the full scale beyond the temperature range of + / - X %, within the scope of temperature compensation readings of + / - X %, without these parameters, will lead to uncertainty in use.

5. Signal output:

There are many kinds of output signals of pressure transmitters, mainly 4... 20 ma, 0... 20 ma, 0... 10 v, 0... 5V and so on, but the more common ones are 4... 20 ma and 0... In these output signals, there are only 4... 20mA is two-wire, the others are three-wire.

Signal output mainly has the mV, V, mA and digital output frequency output, choose the output depends on a variety of factors in the process of enterprise production, such as the controller or display the distance between the transmitter and the system, the existence of electronic jamming signal, whether in larger noise and vibration, etc. For the shorter the distance between the transmitter and controller of the OEM device, using mA output of the transmitter is most economic and effective solution, if you need to output signal amplifier, had better use transducer with built-in amplifier. For long distance transmission or strong electronic interference signal, mA - level output or frequency output is preferred.

If you are in a high RFI or EMI target environment you should consider special protection or filters in addition to selecting mA or frequency output.

6. Excitation voltage:

The type of output signal determines the excitation voltage selected. Many amplifiers have a built-in voltage regulator, so the power voltage range is larger. Wilson of some quantitative configuration, sending device is needs a stable working voltage, therefore, will be able to get a working voltage to decide whether to use sensors with regulator, to comprehensively consider transmitter operating voltage and system cost.

7. Interchangeability of the transmitter:

The selected transmitter should be able to adapt to multiple production processes, which can reduce the cost of the enterprise.

8. Explosion protection and protection level:

Also consider explosion-proof and protection levels for special occasions.