3
Calibration
9
The Micro 600 DO has three measurement modes; DO as % saturation,
DO as mg/L (or ppm) concentration, and temperature.
Dissolved oxygen levels vary with temperature, barometric pressure, and
salinity, so calibration must be performed with consideration of these factors.
It is necessary to set the proper temperature, barometric pressure and
salinity values prior to performing any DO calibration or measurement.
See
Section 3.2 - Temperature Calibration
See
Section 5.2 - Automatic Temperature Compensation
See
Section 5.9 - Pressure & Salinity Adjustment
The Micro 600 DO will accept two % saturation calibration points; 100% using
saturated air or air-saturated water, and 0% using zero oxygen solution. When
100% calibration is performed, the corresponding concentration is adjusted
simultaneously. Therefore, it is not necessary to calibrate the concentration
mode. If calibrating for 0% oxygen, note that the meter will take several
minutes to reach 0% saturation value and constant stirring is not required.
The following table lists calibration values in % saturation calibration mode
with two different barometric pressures. Note that the saturation value
(92.1%) has decreased due to the lower barometric pressure entered.
If calibration is attempted from 10.1% to 49.9%, the “Err.1” message is shown
- calibration is rejected and the display will return to measurement mode.
The Micro 600 DO will accept one calibration point in concentration mode.
The minimum value is 2mg/L (ppm), and the calibration window is +/- 40%
of the factory default value.
Temperature and % saturation calibration should take place
before
attempting
to perform mg/L (ppm) concentration calibration.
3.1 General Information
% Saturation
(per factory default value)
less than 10%
10.1% to 49.9%
50% to 200%
0%
Err.1 (error 1)
100%
0%
Err.1 (error 1)
92.1%
Calibration Value
(760mmHg)
Calibration Value
(700mmHg)
Micro600DO_ZI INST 1240 16/9/15 12:57 Page 9