Product Overview

P499 Series Electronic Pressure Transducers Product/Technical Bulletin4
Checkout
Before applying power, check all wiring connections.
After applying power, operate controlled equipment
under normal conditions and use a reliable set of
pressure gauges to verify that the transducer and the
associated control are operating properly.
0.5 to 4.5 VDC Ratiometric Versions
The ratiometric versions of the P499 transducer
receive a constant 5 VDC (nominal) supply voltage and
vary the output signal voltage, based on the sensed
pressure. The output voltage varies from 10% to 90%
of the supply voltage, providing a 0.5 to 4.5 VDC
(nominal) signal.
To verify that the transducer is working properly:
1. With the transducer in place and the controlled
system pressure stabilized, measure the pressure
at the transducer with an accurate and reliable
gauge. Use this in Step 3 as the measured
pressure, P.
2. Measure the voltage between SUPPLY (red wire)
and COMMON (black wire). Use this in Step 3 as
the measured supply voltage, Vs.
3. Use the equation in Figure 3 to calculate the ideal
output voltage for the ratiometric transducers.
4. Measure the voltage between the transducer
OUTPUT (white wire) and COMMON (black wire)
with a multimeter set to measure DC voltage. This
is the measured output voltage.
5. Compare the ideal output voltage (Step 3) and the
measured output voltage (Step 4). If the measured
output voltage differs greatly from the ideal output
voltage, replace the transducer.
Note: It is normal for the transducer reading to differ
somewhat from pressure gauge readings due to
voltmeter and gauge tolerances, and other factors.
0 to 10 VDC Versions
To verify that the transducer is working properly:
1. With the transducer in place and the controlled
system pressure stabilized, measure the pressure
at the transducer with an accurate and reliable
gauge. Use this in Step 2 as the measured
pressure, P.
2. Use the equation in Figure 4 to calculate the ideal
output voltage for the 0 to 10 VDC transducers.
3. Measure the voltage between the transducer
OUTPUT (white wire) and COMMON (black wire)
with a multimeter set to measure DC voltage. This
is the measured output voltage.
4. Compare the ideal output voltage (Step 2) and the
measured output voltage (Step 3). If the measured
output voltage differs greatly from the ideal output
voltage, replace the transducer.
Note: It is normal for the transducer reading to differ
somewhat from pressure gauge readings due to
voltmeter and gauge tolerances, and other factors.
4 to 20 mA Versions
To verify that the transducer is working properly:
1. With the transducer in place and the controlled
system pressure stabilized, measure the pressure
at the transducer with an accurate and reliable
gauge. Use this in Step 2 as the measured
pressure, P.
2. Use the equation in Figure 5 to calculate the ideal
output current for the 4 to 20 mA transducers.
IMPORTANT: The P499 transducer is a precision
sensing device and testing accuracy is typically
beyond the capability of field diagnostic tools.
Figure 3: Ideal Voltage Calculation for
0.5 to 4.5 VDC Ratiometric Transducers
P
V
o = Vs [0.1 + 0.8 ( )] VDC
Vo= Ideal Output Voltage
Vs= Measured Supply Voltage
P = Measured Pressure
Px = Full Range Pressure of Sensor
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Figure 4: Ideal Voltage Calculation for
0 to 10 VDC Transducers
V
o = 10 ( ) VDC
P
Vo= Ideal Output Voltage
P = Measured Pressure
Px = Full Range Pressure of Sensor
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0
V
Figure 5: Ideal Current Calculation for
4-20 mA Transducers
I = 4 + 16 ( ) mA
P
I = Ideal Output Current
P = Measured Pressure
Px = Full Range Pressure of Sensor
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