Specifications
Instruction Manual    Alpha DO 500 
19 
Press ENT key to confirm the reading. 
NOTES: 
x  The transmitter proceeds to the second point of calibration 
if the displayed reading is less than 10% 
x  The transmitter does not accept the calibration and shows 
calibration error if the displayed (measured) value is more 
than 10% 
4
If the 0% calibration is successful, the Transmitter proceeds to the 
second point. The lower display shows ‘100.0’. Take the electrode out of 
0% oxygen solution, rinse in clean water, dry it and then allow the 
electrode to equilibrate in air. The upper display shows the measured 
value of dissolved oxygen saturation. Allow the reading to stabilize. LCD 
shows ‘READY’ annunciator when the reading is stable. 
Press ENT key to confirm the reading. 
NOTE: 
The transmitter does not accept the calibration and shows 
calibration error if the displayed (measured) value is not with 
50% to 150% 
55
The calibration is completed. The DO Transmitter reverts to 
measurement mode. 
NOTES: 
x  If the displayed value is more than r10% of the high-point value, the 
Transmitter indicates a calibration error by showing ‘ERR’ and blinking 
electrode 
 annunciator. If this happens, press  and  keys together 
to return to measurement mode. Restart the calibration from Step1 
x  To exit from calibration mode without confirming calibration, press  
and  keys together 
x When calibrating with manual temperature compensation, the 
Transmitter automatically changes from preset ‘process temperature’ to 
‘calibration temperature’. After leaving calibration mode, the transmitter 
switches back to the ‘process temperature’ (Refer section 5.4 for 
temperature settings) 










