Temperature remote transmission monitor instrument use and maintenance - Database & Sql Blog Articles

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Since the long-term stability of the instrument has been considered in the design, and the instrument has been aged and verified for a long time before leaving the factory, under normal use, no special maintenance is required.
If the meter is not working properly, the meter output current exceeds 20mA. In most cases, the sensor is open, or it may be caused by a drop in the insulation resistance of the sensor and the protective sleeve (the isolated meter can prevent the fault). If one input is short-circuited, it will not affect the instrument operation. When the circuit is selected by the button, the output current is less than 4 mA and the meter indication is below zero.
Instrument adjustment steps: When the instrument is regularly calibrated, the instrument error needs to be corrected. The following steps can be used to adjust: (take the four-circuit Pt100 input range 0 to 150 °C as an example)
1. Open the instrument panel and turn on the power according to the diagram. First connect the standard resistance box at the input of the first loop, and adjust to 100Ω, and the other loop input terminals are short-circuited.
2. Adjust the potentiometer W11 so that the output is 4 mA and then set the resistance to 157.31 Ω and then adjust W12 to make the output 20 mA. This step is repeated several times to reach a satisfactory accuracy range.
3. Connect the standard resistance box to the second path, and adjust the zero potentiometer W21 and the full-scale potentiometer W22 by the method of step 2, so that the output is 4mA and 20mA respectively. When the second loop is adjusted, the other input loops are also Should be shorted.
4. Connect the standard resistor box to the third and fourth loops separately and repeat step 2. When the potentiometers W31, W32, W41, and W42 are adjusted separately, all four circuits are adjusted.