5
Note: The nominal output value for the various output ranges are designated in the
following order: (0 to 20 mA, 4 to 20 mA, 0 to 10 VDC)
The Basic Calibration should only be performed with an ambient temperature
between 21°C and 29°C. The Basic Calibration was performed on the unit at the
factory and generally does not need to be done again. This procedure initializes the
unit by calibrating the input, and the Ice Point Compensation. The Basic Calibration
should be performed only if a condition exists as described in the “Unit Malfunction”
section. After completion of this calibration, the unit needs to be scaled in Field
Calibration. The Basic Calibration procedure is described below.
Note: To abort this calibration and reset to the previous settings, set the BASIC CAL
switch(#3) OFF prior to the final setting of the OUTPUT CAL switch (Step 4.17)
and turn off power for 5 seconds. Then turn on power and the previous settings will
be loaded.
4.1 Connect a precision mV source with an accuracy of 0.02% to Terminal #7 (TC+
Input) and Terminal #8 (TC- Input). Set the ICE PT EN/DIS switch (#4),
RANGE (#9
), TYPE (#6, #7, and #8), OUTPUT CAL (#1), and FIELD
CAL (#2) switches OFF. Set the BASIC CAL switch (#3) ON.
4.2 Apply power and allow a 30 minute warm-up period. [Output goes to -0.9 mA,
3.4 mA, or -0.5 V nominal]
4.3 Set the OUTPUT CAL switch (#1) ON and then OFF.
4.4 Input -9 mV and wait 5 seconds.
4.5 Set the OUTPUT CAL switch (#1) ON and then OFF.
4.6 Input 6 mV and wait 5 seconds.
4.7 Set the OUTPUT CAL switch (#1) ON and then OFF.
4.8 Input 22 mV and wait 5 seconds.
4.9 Set the OUTPUT CAL switch (#1) ON and then OFF.
4.10 Input 41mV and wait 5 seconds.
4.11 Set the OUTPUT CAL switch (#1) ON and then OFF.
4.12 Input 63 mV and wait 5 seconds.
4.13 Set the OUTPUT CAL switch (#1) ON and then OFF.
4.14 Input 77 mV and wait 5 seconds.
4.15 Set the OUTPUT CAL switch (#1) ON and then OFF.
4.16 Ice Point Calibration.
a. If ice point calibration is not desired, go to step 4.17.
b. To Enable ice point calibration, set the FIELD CAL switch (#2) ON.
1. Connect a precision thermometer (accuracy of 0.1°C) to the unused
terminal beside the TC Input terminals.
2. Allow 5 minutes for the temperature to equalize.
3. Using the temperature indicated by the precision thermometer, input an
equivalent 1 mV/°C signal to the TC Input terminals.
4.17 Set the OUTPUT CAL switch (#1) ON and then OFF.
4.18 Set the BASIC CAL switch (#3) and FIELD CAL switch (#2) OFF. [Output
increases to -0.8 mA, 3.5 mA, or -0.4 V nominal, or more]
4.19 Perform a Field Calibration. (See Section 1.0)
1 2 3 4 5 6 7
9
8
10
ON
1 2 3 4 5 6 7
9
8
10
ON
1 2 3 4 5 6 7
9
8
10
ON
1 2 3 4 5 6 7
9
8
10
ON
1 2 3 4 5 6 7
9
8
10
ON
2
1
ON
4
3
5 6 7 8 9 10
ON
3
1 2
5
4
6 7 8 9 10
ERROR
POWER
VDC+
10
TC+
7
V+
4
I+
1
VDC-
TC-
12
11
9
8
6
5
V-
3
2
I-
POWER SUPPLY
9 to 32 VDC
+
-
VOLTAGE METER
OR
CURRENT METER
ADJUSTABLE
MILLIVOLT
SOURCE
PRECISION
THERMOMETER
Basic Calibration Wiring
Step 4.1
Steps 4.3 to 4.15
Step 4.16
Step 4.17
Step 4.18
4.0 Basic Calibration
Note: The nominal output value for the various output ranges are designated in the
following order: (0 to 20 mA, 4 to 20 mA, 0 to 10 VDC)
The Ice Point Calibration should only be performed with an ambient temperature
between 21°C and 29°C. This Calibration was performed on the unit at the factory
during the Basic Calibration and generally does not need to be done again. The Ice
Point Compensation can be adjusted through this calibration. The Ice Point Calibration
procedure is described below.
Note: Calibration can be aborted by setting the BASIC CAL switch(#3) OFF prior to
the setting of the OUTPUT CAL switch OFF. (Step 3.6)
3.1 Connect a precision mV source with an accuracy of 0.02% to Terminal #7 TC+
Input and Terminal #8 TC- Input. Set the OUTPUT CAL switch (#1) and ICE PT
EN/DIS switch (#4) OFF. Set the BASIC CAL (#3) and FIELD CAL (#2)
switches ON. The positions of switches #5 thru #10 are not relevant for this
calibration procedure.
3.2 Connect a precision thermometer (accuracy of 0.1°C) to the unused terminal (#9)
beside the TC Input terminals.
3.3 Apply power and allow a 30 minute warm-up period. [Output goes to -0.9 mA,
3.4 mA, or -0.5V nominal]
3.4 Using the temperature indicated by the precision thermometer, input an equivalent
1 mV/°C signal to the TC Input terminals and wait 5 seconds.
3.5 Set the OUTPUT CAL switch (#1) ON and then OFF.
3.6 Set the BASIC CAL switch (#3) and FIELD CAL switch (#2) OFF. [Output
increases to -0.8 mA, 3.5 mA, or -0.38 V nominal, or more]
1 2 3 4 5 6 7
9
8
10
ON
1 2 3 4 5 6 7
9
8
10
ON
1 2 3 4 5 6 7
9
8
10
ON
ON
1 2 3 4 5 6 7
9
8
10
Step 3.1
Step 3.5
Step 3.5
Step 3.6
ERROR
POWER
VDC+
10
TC+
7
V+
4
I+
1
VDC-
TC-
12
11
9
8
6
5
V-
3
2
I-
POWER SUPPLY
9 to 32 VDC
+
-
VOLTAGE METER
OR
CURRENT METER
ADJUSTABLE
MILLIVOLT
SOURCE
PRECISION
THERMOMETER
Ice Point Calibration Wiring
3.0 Ice Point Calibration
OUTPUT CAL
FIELD CAL
BASIC CAL
ICE PT DIS/EN
OPEN SEN DN
RANGE
RANGE
DIP SWITCH SETTINGS:
ON = 1
OFF = 0
TYPE
TC
TC TYPE
MODEL ITMA
9-32 VDC
ERROR
POWER
VDC+
10
TC+
7
V+
4
I+
1
VDC-
TC-
12
11
9
8
6
5
V-
3
2
I-
4
2
1
3
7
5
6
8
10
9
Содержание ITMA
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