eutech-instruments ecoscan do 6 do meter User Manual

Page of 76
Instruction Manual 
DO 6 
 
 
12
 
4 CALIBRATION 
4.1 
Important Information on Meter Calibration  
Your meter has three measurement modes namely the DO % saturation 
measurement mode, the DO mg/L (ppm) concentration mode and the 
Temperature measurement mode. 
Since the mg/L (ppm) concentration value of dissolved oxygen varies with 
temperature, barometric pressure and salinity, the meter with its electrode has 
to be calibrated with consideration to these factors to ensure a proper 
measurement. Therefore, it is very important to set the proper temperature, 
barometric pressure and salinity values in the meter prior to any calibration or 
measurement process. Since the dissolved oxygen measurements in % 
saturation will linearly affect the mg/L (ppm) concentration measurement, it is 
important that the meter has to be first calibrated in the % Saturation mode and 
temperature mode before commencing the mg/L (ppm) concentration mode 
calibration. 
In % saturation calibration mode, the dissolved oxygen calibration values will 
vary according to the barometric pressure correction set in the meter. Therefore 
it is necessary to set the barometric pressure first before proceeding to % 
Saturation calibration. The following table is an example which explains the 
acceptance calibration values when % Saturation mode calibration is attempted 
under different absolute value and under two different barometric pressures. 
% Saturation factory 
default value 
Acceptance Calibration Value  
(760mmHg) 
Acceptance Calibration Value  
(700mmHg) 
less than 10% 
0% 
0% 
10.1% to 49.9% 
Err.1 (error 1) 
Err.1 (error 1) 
50% to 200%  
100% 
92.1%