The problem of the safety barrier of the galvanic input, the resistance of the thermal resistance af

Hello lz, the company was founded in 2001 and is located in the water town of Jiangnan. The company is one of the important members of the domestic release industry, and is currently one of the explosion-proof companies with the highest technical requirements for products in China, mainly focusing on the R&D and production of safety barrier equipment.

Suzhou Beijiafu Explosion-proof Electric****[1] is a new modern enterprise specializing in the research and development and production of explosion-proof equipment and undertaking explosion-proof projects. The company's production and operation of safety barriers (mainly production, sales and production of safety barriers) and other explosion-proof equipment, known as a new generation of explosion-proof places "safety guard", Suzhou explosion-proof products for the isolation of dangerous places signal, electric spark and other risk factors have a high degree of achievement, improve the quality of safety barriers has good efficiency, can be widely used in petroleum, petrochemical, refining, chemical, coal, pharmaceutical, military, textile and related national key projects.

You can go and ask them.

The isolated safety barrier at the detection end outputs a single or dual isolated current or voltage signal from the hazardous area to the hazardous area through the isolation barrier, or can be connected to the safety area by serial communication through the configured communication interface. Users can set the input signal type and output range of this product through a special handheld Chinese programmer or computer.

Look at the manual, is there a button on it, can you set the type of couple? Or is there a communication socket that can be set via a computer? Is there a specific model, which manufacturer? You can also go to their official website to check information or consult.

Depending on which type of output you choose, it can be converted to 0-20mA, 4-20mA, 0-10V, 2-10V, 0-5V, 1-5V, etc.

The RTD does not need to pass through the safety barrier, and if necessary, the intrinsically safe temperature change will be used, or the instrument or card with the intrinsically safe input will be directly selected.

The intrinsically safe thermostat output is different in different models, and most of them are 4-20mA or 1-5V standard signals.

Generally, the safety barrier cannot be directly connected to the virtual sun resistance resistance signal.

Generally, it is the thermoelectric differential spring resistance - temperature change (4 20mA) - the mode of the isolation barrier.

Safety barrier or temperature change? Calibrate with a resistance box, and you will know whether it is a problem with the heat sensor or the temperature change.

120 should be around 51, you can check whether the line is grounded, the safety barrier and the wiring of the card is correct.

In addition, the card of DCS should be a thermal resistance card, and the general AI card cannot be connected to thermal resistance.

You can check whether the range of the barrier configuration is the same as the DCS setting!

RTD with a real resistive barrier is not a good thing.

Generally speaking, the so-called thermal resistance and thermocouple safety barriers are often temperature transmitters with safety barrier functions.

Temperature transmitters have a temperature measurement range required. Resistive barriers also have a measurement range, but they are not marked by temperature but by resistance value.

A thermocouple is like a small power supply, and it outputs a mV voltage.

Its internal main capacitors and diodes, the signal will not be distorted, if it is a mutated signal can be checked, if it is continuous, it can not be detected!

Didn't understand what your question meant!!

Thermocouple: Output millivolts (mV).

RTD: Output resistance ( ).

Thermocouples and RTDs do not give them an input signal!!

I do thermocouples, generally the thermocouple output is millivolt units, and the RTD output is ohmic units, which can be changed to a standard 4-20 milliampere current signal through temperature conversion.

Thermocouples and RTDs are contact measurements, which belong to the bottommost measuring element, and there is no input circuit.

RTD input generation fault discrimination method:

1) After the correct wiring is energized according to the instrument wiring diagram, the instrument first displays the thermal resistance index number, then displays the range of the instrument range, and then the lower digital tube of the instrument displays the set temperature, and the upper digital tube of the instrument displays the measured temperature. If the upper row of the digital tube of the instrument shows that it is not the temperature of the heating element, but the rock is "over", "0000" or "000", etc., it means that the input part of the instrument is faulty, and the following checks should be made:

a) Remove the thermal resistance of the above-mentioned fault instrument, and replace it with the thermal resistance connected to the instrument of the same kind of graduation number that is running normally next to it, and after the power is replaced, when the temperature is displayed on the upper row of the digital tube of the original fault instrument, it means that the internal connection of the original thermal resistance is open, and the thermal resistance should be replaced. If the above situation is still the same, it means that the input end of the instrument is damaged during transportation, and the instrument needs to be replaced.

b) Remove the thermal resistance of the above-mentioned faulty instrument, use a multimeter to place it on the ohmic (r)*1 file, and use the two meter rods of the multimeter to measure the two wires of different colors of the thermal resistance. If the resistance value of PT100 RTD is about 100. If the resistance value of Cu50 RTD is about 50.

If the resistance value is very large, it means that the internal wiring of the RTD is open, and the RTD of the same type is replaced. On the contrary, it means that there is a problem with the input part of the instrument, and the instrument needs to be replaced.

2) During the operation of the instrument, the temperature displayed by the digital tube on the upper row of the instrument has a little error with the measured temperature, and the inspection method is used.

a) The RTD material purchased on the market is not the purest and has impurities, which will produce a linear error between ohm value and temperature ( ).

b) If you want to correct the error between the ohmic value and the temperature of a certain temperature point, you can use the measured value in the instrument to correct the "RT" parameter to adjust.

3) When the instrument with correct wiring is running, if the measurement temperature displayed by the digital tube on the instrument is too different from the actual measured temperature, it means that the index number of the instrument and the index number of the thermal resistance are wrong. The following is provided by Beijing Aotemei Automation Technology **** for you free of charge!

Measurement value! First determine whether it is a problem with the connection cable or the RTD itself, and it is also related to the transmitter!