Hach 3650 manual Calibration In Line

3650 Portable O2 Analyzer - Calibrations 33 of 50

4.2.2 Calibration In Line

The in line calibration procedure can be used to calibrate the sensor directly in line, against a liquid sample with a known dissolved oxygen concentration. To perform this type of calibration, the instrument must be set for calibration In line. Switch on the instrument, if necessary, and wait a minute or so for the displayed measurement to settle. Expose the sensor to a liquid sample with a known gas concentration.

1) Press the CAL button. Remember, this button may have been locked out to prevent an accidental reset (see “Locking Out the Instrument’s CAL Button” on page 28 for details).

2) A brief clearing [---]message appears.

3) Press CAL again within a 3 second period.

4) A measurement will flash on the LCD, showing the oxygen concentration of the calibration sample.

5) Assuming you know the gas content to be a certain value, you can adjust the displayed value with the Up/Down Arrow keys.

6) When the reading is adjusted to the known concentration, press CAL again.

7) The instrument displays CAL and returns to the measurement mode.

Operator Manual ORBISPHERE