ABB Z-MT, Commissioning And Calibration Procedures, Page: 20 / 24

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4.6C Analogue Retransmission Output(s) – Fig. 4.2C
Connect the milliammeter in place of the retransmission output to be calibrated, i.e. terminals '1' and '2' for 'O/P MODULE 1',
'O/P MODULE 2' or 'O/P MODULE 3'.
Connect the millivolt source in place of the 'PROBE T/C' connections using copper wire. Switch on.
Notes.
1. The 'PROBE INPUT' must be calibrated before attempting to calibrate the retransmission output(s) – see Section 4.5C.
2. The following procedure is for calibration of retransmission output 1. Retransmission outputs 2 and 3 are carried out in a
similar manner but with the milliammeter connected to the appropriate 'O/P MODULE' terminals.
Select Analogue Retransmission Page.
ANALOGUE RETRANSMISS
5 Times
Advance to electrical calibration procedures.
▲ Operate for approximately three seconds to gain access to the electrical
calibration procedures within the Analogue Retransmission Page.
N o t e . 'x x x x x x' in the following illustrations is a numerical code used for
software analysis during manufacture and can be disregarded.
▼ ▲
or
Advance to next parameter.
Set the milliammeter reading to 0.00mA.
OP1 Zero x x x x x x
SECURE PARAMETERS (Retransmission
Enter
Store.
Retransmission Output 1, Span Calibration
Measure the ambient temperature at the 'CELL T/C' terminals and, from
standard type K thermocouple tables, obtain the millivolt equivalent of this
temperature (a).
Subtract (a) from 55.80 (the theoretical millivolt equivalent of 1400°C for a type
K thermocouple) and set the resultant value on the signal source.
Example. Ambient Temperature: 25°C
Millivolt equivalent: 1.00mV
Set millivolt source to: 55.80 – 1.00(mV) = 54.80mV
Note. The upper display on the ZMT shows the equivalent temperature of the
millivolt signal applied, i.e. 1400°C
OP1 Span x x x x x x
Retransmission Output 1, Zero Calibration
Measure the ambient temperature at the 'CELL T/C' terminals and, from
standard type K thermocouple tables, obtain the millivolt equivalent of this
temperature (a).
Subtract (a) from 0 and set the resultant value on the signal source.
Example. Ambient Temperature: 25°C
Millivolt equivalent: 1.00mV
Set millivolt source to: 0 – 1.00(mV) = – 1 . 0 m V
Note. The upper display on the ZMT shows the equivalent temperature of the
millivolt signal apllied, i.e. 0°C
▼ ▲
or
Set the milliammeter reading to 20.00mA.
Enter
Store.
Repeat for other output(s), if applicable.