About this task
To verify that the transducer is working properly, complete the following steps.
Procedure
- With the transducer in place and the controlled system pressure stabilized, measure the pressure at the transducer with an accurate and reliable gauge. This is the measured pressure (P).
- Determine the maximum (Pmax) and minimum (Pmin) pressure values for the transducer’s pressure range. (See Table 5.)
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Use the equation in Figure 1 to determine the calculated output current for the 4 mA to
20 mA transducers.
Figure 1. Current calculation for 4 to 20 mA transducers
- Measure the P499 transducer output current. To measure the P499 Output current: Disconnect the P499 Output (black) wire from the control input terminal. Set your multimeter to milliamperes (mA). Then connect the multimeter’s red test-lead to the P499 Output (black) wire and the multimeter’s black test-lead to the control input terminal. The milliamperes (mA) reading on your multimeter is the measured output current.
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Compare the calculated output current (Step 3) to the measured output current
(Step 4). If the current from measured output current differs greatly from the
calculated output current, replace the transducer.
Note: It is normal for the transducer reading to differ somewhat from pressure gauge readings due to multimeter and gauge tolerances, and other factors.