Azbil C1M - Page 282

12-4
Chapter 12. Calibration and Inspection
Handling Precautions
• When calibrating the PV input, be sure to adjust all gains according to the
model that is used.
• Do not leave the PV input terminals open during the warm-up from
power-on to the start of calibration. Set the thermocouple input to 0 mV
and the DC voltage input to 0 V (or short circuit the terminals). For the
RTD, set the input to 100 Ω (or short circuit the terminals).
z
Current transformer (CT) input calibration
(1) Select the [CT Input Calibration] tab.
(2) Select the channel to calibrate.
(3) Select [Zero] in the [Zero/Span] field.
Both zero and span should be calibrated for one channel. Therefore, after
selecting a channel, first calibrate zero and then span.
(4) Press [Read].
(5) Keep applying the zero calibration current to the CT input terminals of the
selected channel for 30 seconds or longer. Before application of current,
connect this device to the measuring instrument as shown.
Current generator
CT input 1
Model C1M
−
+
Current generator
CT input 2
Model C1M
−
+
(6) Press [Write].
(7) Select [Span] in the [Zero/Span] field.
(8) Press [Read].
(9) Keep applying the span calibration current to the CT input terminals of the
selected channel for 30 seconds or longer.
(10) Press [Write].
(11) If there are other channels to calibrate, return to step 4.
Handling Precautions
• When calibrating the CT input, apply a DC current (mA) to the input
terminals.