DayTronic 3500 Series, Instruction Manual

Page: 81 / 122

4.d.2 “T
WO
-P
OINT
” C
ALIBRATION
ZERO (ZRO): ZRO=z [CMT]
Sets the ZERO OFFSET ("b" term) that is to be used whenever "MXB" calibra-
tion is in effect such that the existing input yields a reading of "z" (full range is
±32700). When used in "TWO-POINT" calibration, must precede the
FORCE
(FRC) command.
IMPORTANT: THIS COMMAND SHOULD ONLY BE APPLIED WHEN THE 3500
INSTRUMENT IS SET FOR "TWO-POINT" OR "CALCULATED" CALIBRATION—
THAT IS, WHEN THE
CAL=MXB [CMT] COMMAND IS IN EFFECT. IF
ENTERED WHEN CAL=LIN [CMT] , UNPREDICTABLE READINGS COULD
OCCUR. The "READ" form of the ZRO command will not be recognized.
FORCE (FRC): FRC=z [CMT]
Sets the SCALING FACTOR ("m" coefficient) that is to be used whenever
"MXB" calibration is in effect such that the existing input yields a reading of "z"
(full range is ±32700). Also sets desired precision (decimal-point location).
When used in "TWO-POINT" calibration, must be preceded by
ZERO (ZRO)
command.
IMPORTANT: THIS COMMAND SHOULD ONLY BE APPLIED WHEN THE 3500
INSTRUMENT IS SET FOR "TWO-POINT" OR "CALCULATED" CALIBRATION—
THAT IS, WHEN THE
CAL=MXB [CMT] COMMAND IS IN EFFECT. IF
ENTERED WHEN CAL=LIN [CMT] , UNPREDICTABLE READINGS COULD
OCCUR. The "READ" form of the FRC command will not be recognized.
Note: The two following commands apply only to the Model 3570 DC STRAIN
GAGE CONDITIONER and the Model 3578 AC STRAIN GAGE CONDITIONER.
SHUNT CALIBRATE—POSITIVE:
SHP=ON [CMT] or SHP=OFF [CMT]
Closes or opens the instrument’s positive calibration shunt. SHP=ON [CMT]
should be preceded by a ZERO (ZRO) command (above) and should be fol-
lowed by a command of FRC=X [CMT] , where "X" is the EQUIVALENT INPUT
produced by the shunt (to calculate "X," see Section 4.c.3). SHP=OFF [CMT]
should then be applied to resume normal measurement. See also Appendix
F for the interaction of
SHP with the logic-input shunt commands.
SHUNT CALIBRATE—NEGATIVE:
SHN=ON [CMT] or SHN=OFF [CMT]
Closes or opens the instrument’s negative calibration shunt. SHN=ON [CMT]
should be preceded by a ZERO (ZRO) command (above) and should be fol-
lowed by a command of FRC=X [CMT] , where "X" is the EQUIVALENT INPUT
produced by the shunt (to calculate "X," see Section 4.c.3). SHN=OFF [CMT]
should then be applied to resume normal measurement. See also Appendix
F for the interaction of
SHN with the logic-input shunt commands.
4.d.3 15-S
EGMENT
L
INEARIZATION
Your 3500 instrument need NOT be set to CAL=LIN [CMT] in order for the follow-
ing linearization-related commands to be effective. Commands that change the
linearization table will not affect present calibration as long as
CAL=MXB [CMT] .
The indicated changes will go into effect, however, as soon as the instrument is
4.19
S
ETUP
: I
NSTRUMENT
C
ALIBRATION
4
4.d C
ALIBRATING
T
HROUGH THE
RS-485 I
NTERFACE