Instruction manual
Instruction manual  αlpha DO 2000 
12 
4   NORMAL OPERATION 
4.1  Measurement mode  
When the controller/transmitter is powered on, the display first shows all segments briefly, 
after which the controller/transmitter automatically enters into the Measurement mode. 
Please note: To guarantee accurate readings the measuring system (transmitter 
and sensor) must be calibrated. 
MEAS
°C
ATC
%
13.0
The mode indicator “MEAS” at the top of the display indicates that the transmitter is in 
Measurement mode. The upper alpha-numerical display shows the measured dissolved 
oxygen value, while the lower display shows the temperature value. 
From Measurement mode you can access Calibration mode and Setup mode by pressing 
the CAL key or ENT key followed by the corresponding security code. For detailed information 
refer to section 5 “Calibration mode” or section 6 “Setup mode”, respectively. 
By pressing the REL key in Measurement mode you can view the actual relay set points. By 
pressing the MODE key followed by the corresponding security code in Measurement mode 
you can switch relay operation mode from automatic to manual. 
For detailed information refer to section 7 “Relay Modes”. 










