Eurotherm 2408i, Руководство пользователя, Страница: 58 / 66

Engineering Manual 2408 i Indicator
56
Part Number HA027240 Issue 5.0 Feb 2015
4.7 Indicator calibration
This section explains how to calibrate PV inputs 1 and 2, and retransmission outputs. It should not be confused with
User Calibration described in section 3.6 which allows the user to add offsets to compensate for external
measurement inaccuracies. Calibration of the indicator should not normally be necessary and must only be carried
out using calibrated reference sources. It is always possible to revert to factory calibration settings if necessary.
4.7.1 To Calibrate Input 1 or 2
Figure 4-10: mV Input Calibration
4.7.1.1 To Calibrate mV or Volt Inputs:-
Do This This Is The Display You Should See Additional Notes
4.7.1.2 To Calibrate CJC
In addition, for thermocouple inputs, calibrate Cold Junction Compensation (CJC), as follows:-
Do This This Is The Display You Should See Additional Notes
1. Replace the copper cable from the mV source with the appropriate compensating cable
2. Configure the indicator for a thermocouple type. A base metal thermocouple such as type K is recommended
3. Set the mV source to the same thermocouple compensation
4. Set the mV source to 0.000mV
•
A mV calibration should be carried out before thermocouple
and RTD calibrations.
•
Connect a mV, volt source to the input which you wish to
calibrate.
•
If the input is RTD connect a resistance box.
Copper cable
mV Source
2400 i Indicator
Input 1 or 2
terminals
5. From the
< PV
>
list press or
as many times as necessary
to access
<
CJC
>
CJC
PV
When the indicator is
calibrating the message
< buSY
>
is shown. When
complete the message
< donE
>
is flashed briefly and
the display returns to
< GO >
.
The CJC calibration is now
complete.
.YES
GO
6. Press to show <
GO
>
7. Press or to select
<
YES
>
GO
donE
buSY



1. From any display press as
many times as necessary to
access the
< CaL >
List’ header
CAL
Set the mV source to 0.000mV
2. Press to show
< rcAL >
3. Press or to select input 1
or 2
< PV.1 >
or
< PV.2 >
PV.1
rcAL
This allows you to choose the parameter
to be calibrated
When the indicator is
calibrating the message
<
buSY
>
is shown. When
complete the message
< donE >
is flashed briefly
and the display returns to
< GO >
. The low point
calibration is now complete
.YES
GO
4.
Press to show
<
PV
>
5.
Press or to select
< mv.L >
mv.L
PV
6. Press to show
< GO >
7. Press or to select
<
YES
>
For 0 - 10V input range and high
impedance input range,
set the volt source to 0.000V
mv.H
PV
8.
Repeat the above steps for
< mV.H >
Set the mV source to 10.000mV
For 0 - 10V input range, set the volt source
to 10.000V
For RTD input range, set the resistance
box to 400.00
Ω
For high impedance input range, set volt
source to 1.000V
GO
donE
buSY