3-10 / Calibration 2808B
2. Set the Dip and Rotary switches in accordance with Table 3-B. Suppressed zero values
are expressed as negative percentages of upper range limit (URL). Zero percent URL
represents no suppression. If the desired percent suppression is in between values, try
the next closest setting.
3. Apply a 100% pressure input to the transmitter equivalent to the upper range value
(URV). For this example, URV = 80 psi.
4. If Transmitter output is not 5.000V (20.00mA), adjust A1 to make a minor correction.
5. Lower the input pressure to P
min
. Adjust A2 to set the output to 1.000V (4.00mA).
6. Recheck the Transmitter output with 0%, and 100% inputs. The DMM should provide
respective readings of 1.000V (4.00mA), and 5.000V (20.00mA) (± 0.15% full scale).
7. If necessary, repeat the A1 and A2 adjustment procedures.
8. If problems persist, recheck the DIP switch settings. Try setting the switches to the
lower percentage. For instance, if the desired percent suppression is -85%, set the
switches for a suppression of -90%.
Figure 3-3 - Water Tower Level Measurement - Zero Suppression
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