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section V
Model
DRC-93c
5 . 6 . 2
Set
Point
Voltage Calibration
Set a set point and gain value
which results in full scale output
Calibrate the Set Point Voltage as
on the
MAX
Heater Range scale.
follows:
2 .
With full power across the load
1 .
Remove the instrument cover.
resistor on the
-1
scale, place
the DVM LO probe in
TP19
PWR
V+
2.
Calibrate
with
the
Control
and the DVM HI probe
in
TP21 and
Switch selecting either a 9210
adjust
PWR
V+
until
the DVM
or 9220 Input Card and the
-3
reads 1.000 volts.
There now
configuration.
If the DRC-93C
should be one ampere through the
does not contain one of these
load (1.5 amperes in the case of
input cards, calibrate the set
the
W60).
The heater can now be
point by following the procedure
described with that Input Card.
3.
Place the DVM LO into TP15
PWR
3.
To calibrate the Set Point volt-
V- and the DVM HI into TP17 HTR
age with a 9210 or 9220 card,
V+ and adjust PWR V- ADJ until
connect the LO lead of your DVM
the DVM reads
1.0000
volts.
to
TP1
and the HI lead to TP25
SP
v.
4. Place the DVM
LO into TP20
FWR
LD and the
DVM
HI into TP16 VREF
4.
Enter a
set
point of
0.0000V
and
and adjust PWR
VREF
until the
adjust the potentiometer labeled
DVM reads
1.0000
volts.
SP ZERO
ADJ
until the DVM reads
0.0000
volts.
5. Repeat
3
and 4 until they do not
change.
5.
Enter a set point of 2.7000V and
adjust the potentiometer labeled
Note:
TP 24 CNT V
is
the control
SP SPAN ADJ until the DVM reads
voltage.
For the 9210/20-3 it is
-2.7000 volts.
the voltage across the sensor; for
the 9210/20-6 it is 0.45 times the
6.
Repeat the two settings until
voltage across the sensor.
TP
25
is the set point voltage and is of
opposite sign from TP 24.
These
5 . 6 . 4
Calibration of Power Output
two
voltages algebraically sum to
the error signal.
If the heater output is not the
standard 50 watts for the DRC-93C,
the optional power output installed
5 . 7
TROUBLESHOOTING
should be indicated on the front
page of this manual.
1.
Verify
that
the
back
panel
tained in this Section.
HEATER
RESISTANCE switch is on
10-25 and use a load resistor
5 . 7 . 1
Sensor Current
between 10 and 25 ohms with a
wattage rating equivalent to its
If the sensor current is not within
resistance.
The W60 output re-
specifications (Section 5.5.3) then
quires a load between 10 and 25
adjust the current trimpot on the
ohms with a wattage rated 1.5
input card (Section VII)
.
times the resistance value.
turned off.
the values are constant.
Information on troubleshooting the
Model DRC-93C controller is con-
5-6
COPYRIGHT 3/88 LSCI
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