6
VOLTAGE CALIBRATION
1. Connect a precision Voltage Source with an output range of -10.000 to 60.000
mV and an accuracy of 0.03% or better to the TC- (#5) and TC+ (#3)
terminals. Cold junction calibration must be performed AFTER voltage
calibration.
2. Enter the Program Menu and step through the Program Menu list by pressing
the “SEL” button until
CAL
is displayed.
3. Press the “blank” button to change
no
to
YES
. Press “SEL”.
4. The display shows
00000.
Use the “blank” button to increment the access
code to
00006.
Press and hold “SEL”.
5. After entering the correct access code, the unit will display
IN1
. Follow the
table below for calibration sequence.The unit displays
CALC
for about 3
seconds after pressing the “SEL” button before proceeding to the next input
point.
6. After voltage calibration is complete, the unit will return to the
CAL
program
item. Exit programming and verify various points from -10.00 to 60.00
mVDC using the Voltage Calibration Check procedure to ensure that the
calibration is correct.
7. Repeat calibration if necessary.
COLD JUNCTION CALIBRATION
This procedure must be performed AFTER an accurate voltage calibration.
The ambient temperature at which this calibration should be performed is 15 to
35 °C (59 to 95 °F). A Temperature indicator with 0.1 °C resolution and
accuracy is required to perform this calibration.
1. Enter Programming Menu, and verify the following:
tyPE
= probe being connected to the unit.
CJC
=
YES
dISP
=
0.0
°
C
OFSEt
=
0
Make any necessary changes to programming.
2. Connect a thermocouple probe of known accuracy and type (J, K, E, T, or N)
to the CUB4TC. The probe should match the one selected in programming.
3. Connect a reference temperature probe to measuring end of the CUB4TC
thermocouple.The two probes should be shielded from air movement and
allowed sufficient time (15 minutes minimum) to equalize in temperature.
(As an alternative, the CUB4TC thermocouple probe may be placed in a
calibration bath of known temperature.)
4. Compare the unit display with reference temperature indicator (or calibration
bath). If the displayed unit temperature does not equal the reference probe
temperature, calculate the CJ error as follows:
CJ Error = reference probe temperature - CUB4TC displayed temperature
5. Enter the Program Menu and step through the Program Menu list by pressing
the “SEL” button until
CAL
is displayed.
6. Press the “blank” button to change
no
to
YES
. Press “SEL”.
7. The display shows
00000.
Use the “blank” button to increment the access
code to
00003.
Press and hold “SEL”.
8. After entering the correct access code, the display will alternate between
CJC
and the current cold junction compensation value.
9. If the current CJC value is 0.0 °C or 59.9 °C, set the
CJC
value to the current
ambient temperature, exit calibration, and repeat the CJC calibration
procedure.
10. Otherwise, the new value to be entered is the sum of the current value and
the CJ Error recorded previously.
11. Exit the Programming Menu and repeat the calibration from Step 4 to verify
accuracy.
Voltage Calibration Wiring
DISPLAY
PARAMETER
ACTION
IN1
-10.000 mV
Apply -10.000 mV, wait 5 sec., press
SEL
IN2
0.000 mV
Apply 0.000 mV, wait 5 sec., press
SEL
IN3
10.000 mV
Apply 10.000 mV, wait 5 sec., press
SEL
IN4
20.000 mV
Apply 20.000 mV, wait 5 sec., press
SEL
IN5
30.000 mV
Apply 30.000 mV, wait 5 sec., press
SEL
IN6
40.000 mV
Apply 40.000 mV, wait 5 sec., press
SEL
IN7
50.000 mV
Apply 50.000 mV, wait 5 sec., press
SEL
IN8
60.000 mV
Apply 60.000 mV, wait 5 sec., press
SEL
Cold Junction Calibration Wiring
