Thus, to calibrate a 10A68-2-based Channel No. “x,” you need only turn ON the system
EEPROM SWITCH and then apply the following
SCALING FACTOR (EMM) command:
EMM x = m [CR]
where “m” equals the full-scale range corresponding to the channel’s present TYPE
designation, expressed to the precision desired for the channel’s data readings.
Channel “type” codes and associated full-scale ranges are given in Table 2, above. If,
for example, a voltage-measuring 10A68-2 channel is “typed” as “65” (corresponding
to a full scale of 2 V-AC) and you want the channel to read
tenths of a volt, you would
enter an “m” value of “2.0.”
NOTE: The accuracy of “absolute” calibration of a 10A68-2-based channel is limited to
±0.1% of full scale for all input ranges except 5 A, for which it is limited to ±0.5%.
TWO-POINT (DEADWEIGHT) CALIBRATION
Using the standard ZERO (ZRO) and FORCE (FRC) commands, this conventional
“zero and span” method can be applied to a 10A68-2 channel if the received voltage
or current input is an
analog of another parameter which has one or more indepen-
dently and accurately known calibration values. It can also be used to improve the
ABSOLUTE calibration of an input that measures voltage or amperage itself (beyond
the 10A68-2 card’s inherent limit of ±0.1% or ±0.5% of full scale).* The mainframe’s
EEPROM Write Protect Switch must be ON for the ZRO and FRC commands to be
effective. See Manual Section 1.G.5 for a general discussion of this calibration tech-
nique.
10A68-2.4 SETUP AND/OR OPERATING CONSIDERATIONS
*±0.5% for the 5-A input range; ±0.1% for all other input ranges.
10A68-2 DUAL AC RMS CARD
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