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<7. START-UP>
7-2
IM 11P03A03-01E 6th Edition : Jan. 26, 2022-00
7.2 Warm-up
After power up the instrument goes through a warm-up period and then reaches steady state
where it is ready for measurement. This section describes how the instrument behaves during
the warm-up period.
The instrument controls the temperature so that the temperature in the sensor unit is kept at 60
°C. It may take approximately three hours until the temperature in the sensor unit has stabilized
at 60 °C. The required time varies depending on the temperature in the sensor unit at start-up
or ambient temperature. When the temperature in the sensor unit approaches 60 °C, the DATA
display shows oxygen concentrations and the MAINT lamp starts to blink. At the same time the
instrument provides analog outputs corresponding to the output range. This period is called a
stabilization period and in this period a temperature drift may occur since the temperature in the
sensor unit has not completely stabilized. A calibration cannot be executed in this period. When
the temperature in the sensor unit stabilized completely, the MAINT lamp stops blinking and the
MEAS lamp turns on. This is steady state. During a warm-up period the analog output is fixed
at 4 mA. During warm-up and stabilization periods the maintenance status contact is activated.
Figure 9.2 shows the temperatures of the heater and in the sensor unit during warm-up and
stabilization periods.
Heater Temperature (shown on DATA display)
Temperature in
Sensor Unit
Power Up
Temperature
Time
Warm-up Period
Stabilization
Period
MAINT Lamp Blinking
Steady State
60 °C
Maintenance Status Contact Action
Open
Closed
F10.1E.ai
Figure 7.1 Temperatures of the Heater and in the Sensor Unit During Warm-up and Stabilization Periods
7.3 Analog Output Loop Check
A loop check is for checking wiring between the analog output (terminals 3 and 4) of the
instrument and the terminals of a higher-level device.
(1) Switch to MAINT mode and enter the password.
(2) Change the Function Number to “16.”
(3) Press the ZERO key to provide 4mA output from the output terminals.
(4) Press the SPAN key to provide 20 mA output from the output terminals.