142 | RMC-100| 2105552MNAE
Figure 7-24: Target values for user-defined range
15. Click Low Cal Point. The Enter Low Calibration Value dialog displays the default target low
value of zero (0.000 PSI) (Figure 7-25
). The Current Reading field displays a voltage value of
approximately 0 which indicates that the calibrator has not applied any signal to the AI.
The Current Reading field value (Figure 7-25) does not reflect the value for
the electrical current applied to the AI. The RMC displays the voltage value detected across the AI’s
internal resistance (or impedance). The internal resistance is approximately 250
Ω (See analog
input specifications for c
urrent mode AIs in Tab le 2-10). For the required 3-
point current calibration
values of 4, 12 and 20 mA, the displayed voltage should be approximately 1,
3 and 5.0 Vdc
respectively. To determine voltage values for different current inputs, multiply the current value by
250 (V=I*R).
The term “current” in the Current Reading and Current Value fields in the calibration screens,
means real time. The value displayed is what the AI detects as soon as the external device supplies
the signal. Voltage values display before calibration completes. After calibration, values from the
user
-defined range display.
To Next Page
Loading...
