Specifications
Instruction Manual    Alpha DO 500 
33 
6. Technical Specifications 
General Specification 
(a) Dissolved Oxygen (% saturation) 
Measuring Range  0.00 to 199.9 % 
Resolution 0.1 % 
Relative Accuracy  ± 1.5% of full-scale reading 
(b) Dissolved Oxygen (ppm or mg/l) 
Measuring Range  0.00 to 19.99 ppm or 0.00 to 19.99 mg/l 
Resolution  0.01 ppm or 0.01 mg/l 
Relative Accuracy  ± 1.5% of full-scale reading 
(c) Temperature 
Measuring range  0.0 to +100.0 
o
C 
Resolution 0.1 
o
C 
Relative accuracy  ± 0.5 
o
C 
Sensor 
Pt100 (2 wire or 3 wire) 
Calibration 
(a) Dissolved Oxygen 
Number of calibration points  1 or 2 points 
(b) Temperature 
Offset Adjustment  ± 10 C 
Compensation 
Temperature Compensation  Automatic or Manual (0 to 50
 o
C) 
Pressure Compensation  0.74 to 3.00 BAR 
550 mmHg to 2250 mmHg (225 cmHg) 
10.7 to 43.5 PSI 
(Manual setting and automatic correction) 
Salinity Compensation  0.0 to 50.0 ppt 
(Manual setting and automatic correction) 
Output Parameters 
Output Current  4 to 20 mA (Galvanically Isolated) 
Over/Under Range Output 
Current 
ON Select : 3.8 mA 
OFF Select: 4 mA (under range), 20 mA (over 
range) 
HOLD Output Current  ON Select : 22 mA 
OFF Select : Last measured current 
Load Resistance  600 ohms (max.) at 24V 
Display 
LCD  7 segments display with symbols for status 
information 
Electrical Data and Connections 
DO Input  Screw Terminal (3.5mm pitch) 
Connection terminal  8-pin & 3-pin terminal blocks 










