3.d CONFIGURATION AND CALIBRATION
For initial configuration of ANALOG INPUT CHANNELS dedicated to a specific Model
AA30-4 card when used in System 10, see the general remarks on System 10 “real-
channel” configuration in Manual Section 1.G.1 and elsewhere in the
System 10 Guide-
book
. For AA30-4 channel “type” codes, see Table 1, above.
In System 10, a relatively linear Model AA30-4 channel normally employs
TWO-POINT
(DEADWEIGHT) CALIBRATION
.* See Manual Section 1.G.5 for a general discussion
of this conventional “zero and span” calibration technique. Note, however, the follow-
ing special procedure that applies to an LVDT-based Channel No. “x”:
1. Make sure the channel has been properly “typed” and “located” (see Manual Sec-
tion 1.G.2).
2. Turn ON the system EEPROM SWITCH and enter a command of
BEE x = 0 [CR]
This command sets an initial ZERO OFFSET (“b” term) of zero for Channel No. x.
3. Observing a “live” reading of the channel, mechanically adjust the fixture and
physical position of the LVDT until the lowest reading occurs. This is the LVDT's
“electrical null” point.
4. With the transducer still in “null” position, enter a command of
ZRO x [CR]
5. Displace the LVDT probe by a precisely known distance, preferably between 80%
and 100% of the transducer's nominal full-scale rating.
6. Command
FRC x = z [CR]
where “z” is the exact value of the displacement produced in Step 5, expressed in
appropriate engineering units (the precision of the final measurement will match
that of the entered “z” value).
7. Repeat Steps 4, 5, and 6, if necessary, until the LVDT's zero and span points coin-
cide with the calibration block or micrometer reference being used.
AA30-4.10 SETUP AND/OR OPERATING CONSIDERATIONS
AA30-4 QUAD LVDT CARD
*For nonlinear channels, “custom linearization” can be used (see Manual Section 2.L).
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