Setra System Model 730 - Manual (Page 10)

4.0 OPERATION
For most accurate pressure measurement, allow the Model 730 to warm
up for at least 15 minutes. After installation, periodically check the zero
output reading to verify correct output. Adjust the zero potentiometer if
incorrect (See Section 5 for zero adjustment instructions).
The signal output of the Model 730 is linear with pressure; e.g., for a 10
VDC FS Model 730, 10 VDC equals 100% FS output; 1 VDC equals 10% FS
output.
Table 1 indicates the lowest pressures recommended for reading and
pressure control for each range of the Model 730. The lowest suggested
pressure for reading is limited by the resolution and the accuracy of the
Model 730. This is directly related to the electrical noise on the signal
output and can be significantly effected by incorrect electrical ground
connection, or connection to an electronically noisy power supply or
readout instrument. Improved results may be obtained if the transducer
is operated in an environment with stable temperature and air flow. The
lowest recommended pressure used for control applications, such as a
closed loop downstream pressure control system, is based on a minimal
signal output of 50 mV.
Note 1: if the unit has been exposed to sudden environmental changes, allow at least 2 hours
before making any adjustments
.
Table 1: Recommended Lowest Pressures
Available for Reading & Pressure Control
Recommended Lowest Recommended Lowest
Full Scale Range Pressure Reading Pressure for Control
10 Torr 0.005 Torr 0.05 Torr
20 Torr 0.010 Torr 0.10 Torr
50 Torr 0.025 Torr 0.25 Torr
100 Torr 0.050 Torr 0.50 Torr
200 Torr 0.100 Torr 1.00 Torr
1000 Torr 0.500 Torr 5.00 Torr
10 mbar 0.005 mbar 0.05 mbar
100 mbar 0.05 mbar 0.5 mbar
1000 mbar 0.5 mbar 5 mbar
1 kPa 0.0005 kPa 0.005 kPa
2 kPa 0.0010 kPa 0.010 kPa
5 kPa 0.0025 kPa 0.025 kPa
10 kPa 0.0050 kPa 0.050 kPa
20 psia 0.0100 psia 0.100 psia
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