- The transmitter has no output
1. 1: Check whether the power supply of the transmitter is reversed; Solution: Connect the power supply polarity correctly。
1.2: Measure the power supply of the transmitter to see if there is a 24V DC voltage; Solution: The power supply voltage supplied to the transmitter must be ≥ 12V (i.e., the voltage of the input terminal of the transmitter ≥ 12V). If there is no power supply, check whether the circuit is disconnected and whether the detection instrument is selected incorrectly (the input impedance should be ≤250Ω);
1.3: If it is with a meter head, check whether the meter head is damaged (you can short circuit the two wires of the meter head first, if it is normal after short circuit, it means that the meter head is damaged); Solution: If the meter head is damaged, you need to replace the meter head.
1.4: Serial the ammeter into the 24V power supply circuit to check whether the current is normal; Solution: If it is normal, it means that the transmitter is normal, and you should check whether the other instruments in the circuit are normal.
1.5: Whether the power supply is connected to the power input of the transmitter; Solution: Connect the power cord to the power terminal.
2. Transmitter output ≥ 20mA
1: Is the transmitter power supply normal? Solution: If it is less than 12VDC, check if there is a large load in the circuit. The input impedance of the transmitter load should meet RL ≤ (transmitter power supply voltage -12V)/(0.02A) Ω
2: Does the actual pressure exceed the selected range of the pressure transmitter; Solution: Choose a pressure transmitter with an appropriate range again.
3: Is the pressure sensor damaged? Severe overload can sometimes damage the isolation diaphragm. Solution: It needs to be sent back to the manufacturer for repair.
4: Whether the wiring is loose; Solution: Connect the wires and tighten them 5: Is the power cord wired correctly? Solution: The power cord should be connected to the corresponding terminal post
3:AOutput≤4mA
1: Is the transmitter power supply normal? Solution: If it is less than 12VDC, check if there is a large load in the circuit. The input impedance of the transmitter load should meet RL ≤ (transmitter power supply voltage -12V)/(0.02A) Ω
2: Does the actual pressure exceed the selected range of the pressure transmitter; Solution: Re select a pressure transmitter with an appropriate range
3: Is the pressure sensor damaged? Severe overload can sometimes damage the isolation diaphragm. Solution: It needs to be sent back to the manufacturer for repair.
4、 Incorrect pressure indication
1: Is the transmitter power supply normal? Solution: If it is less than 12VDC, check if there is a large load in the circuit. The input impedance of the transmitter load should meet RL ≤ (transmitter power supply voltage -12V)/(0.02A) Ω
2: Is the reference pressure value necessarily correct? Solution: If the accuracy of the reference pressure gauge is low, it is necessary to replace it with a higher accuracy pressure gauge.
3: Is the range of the pressure indicating instrument consistent with the range of the pressure transmitter? Solution: The range of the pressure indicating instrument must be consistent with the range of the pressure transmitter
4: Is the input and corresponding wiring of the pressure indicating instrument correct? Solution: If the input of the pressure indicating instrument is 4-20mA, the output signal of the transmitter can be directly connected; If the input of the pressure indicating instrument is 1-5V, a resistor with an accuracy of one thousandth or more and a resistance value of 250 Ω must be connected to the input end of the pressure indicating instrument, and then connected to the input of the transmitter.
5: The input impedance of the transmitter load should comply with RL ≤ (transmitter supply voltage -12V)/(0.02A) Ω Solution: If it does not comply, corresponding measures can be taken according to its different characteristics, such as increasing the supply voltage (but must be below 36VDC), reducing the load, etc
6: Check if the input terminal of the multi point paper recorder is open when there is no recording; Solution: If there is an open circuit: a. It cannot carry other loads; b. Use another recorder with an input impedance ≤ 250 Ω when there is no record.
7: Is the corresponding equipment casing grounded? Solution: Equipment casing grounding
8: Whether to separate the wiring from AC power and other power sources Solution: Separate the wiring from AC power and other power sources
9: Is the pressure sensor damaged? Severe overload can sometimes damage the isolation diaphragm. Solution: It needs to be sent back to the manufacturer for repair.
10: Whether there are sand, impurities, etc. blocking the pipeline, which can affect the measurement accuracy; Solution: It is necessary to clean up impurities and add a filter screen in front of the pressure interface.
11: Is the temperature of the pipeline too high? The operating temperature of the pressure sensor is -25~85 ℃, but in actual use, it is best to be within -20~70 ℃. Solution: Add a buffer tube to dissipate heat. It is best to add some cold water inside the buffer tube before use to prevent overheating steam from directly impacting the sensor, thereby damaging the sensor or reducing its service life.
Post time: Nov-21-2023