Yamatake Corporation
5-36
ST3000 Smart Transmitter Series 900 Electronic Differential Pressure/Pressure Transmitter
5-4-2 :Liquid Level Measurement
5-4-2-1 Preparation for Measurement
WARNING
• Make sure that the process is in the manual control mode.
If the process is in the automatic control mode, make sure that it has been changed
to the manual mode.
• For hazardous fluids (poisons etc.) take any necessary actions to prevent
physical hazard and ensure that work proceeds with adequate care.
• Ensure closure of the main valve, the drain valve, and the gas vent plug
on the pipe (Refer to Figure 4-12).
Setting range calculation:
In determining the setting range by calculation, refer to Item "5-10 : Set Range Calcu-
lation for Liquid Level Measurement"
Gas pressure measurement
Perform zero-point calibration and introduce process pressure, by this procedure:
• Zero point calibration
• Introducing process pressure and venting air
Step
Description
1
Open the drain plug to release the pressure receiving part to the open air.
If fluid remains in the pressure receiving part, blow out fluid.
2
Referring to procedure2 in page 5-10, perform zero-point calibration.
3
When calibration is complete, close the vent plug.
Step
Description
1
1. Gradually open the main valve (Refer to Figure 4-12) to introduce the
process pressure into the connecting pipe.
2. After introducing the process pressure into the pressure receiving part
of the transmitter, close the main valve.
2
Ensure zero leakage exists at the connecting pipe and transmitter.
