OTT Hydrolab DS5, Руководство пользователя

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Operation
4.2.4 Temperature Sensor Calibration
The temperature sensor is factory-set and does not require recalibration.
4.2.5 Specific Conductance Calibration
Note: TDS measurements are based on specific conductance and a user-defined scale factor.
The factory default scale is 0.64 g/L / mS/cm.
This procedure calibrates TDS, raw Conductivity, and Salinity. Specific conductance
requires a two-point calibration. Calibrate the sensor to zero and then to the slope buffer.
1.
Pour the specific conductance standard to within a centimeter of the top of the
Calibration Cup.
2.
Make sure there are no bubbles in the measurement cell of the specific
conductance sensor.
3.
Enter the SpCond standard for mS/cm or µS/cm using Hydras 3 LT software or a
Surveyor.
4.2.6 Clark Cell Dissolved Oxygen Sensor Calibration
Dissolved oxygen calibrations can be performed using water-saturated air or using a
water sample with a known dissolved oxygen concentration.
Note: Dissolved oxygen can also be calibrated in a well stirred bucket of temperature-stable,
air-saturated water. This situation resembles the actual field measurement conditions, but is more
difficult to accomplish reliably.
4.2.6.1 Water-Saturated Air Dissolved Oxygen Calibration
CAUTION
The saturated-air method is valid only for the Clark Cell dissolved oxygen sensor. If
calibrating the Hach LDO sensor, refer to the Hach LDO Instruction Sheet
(Cat. No. 00745589).
Note: Calibration of D.O. % Saturation also calibrates D.O. mg/L.
1.
Fill the Calibration Cup with deionized or tap water (specific conductance less than
0.5 mS/cm) until the water is just below the membrane O-ring. Do not allow water to
contact the membrane or the O-ring.
2.
Carefully remove any water droplets from the membrane with the corner of a tissue.
3.
Turn the black cap upside down (concave upward) and lay it over the top of the
Calibration Cup. This stops the exchange of air and allows the local environment to
equilibrate. Wait for the reading to stabilize.
4.
Determine the true barometric pressure for entry as the calibration standard.
Barometric pressure information can be obtained from a local weather station or
airport or the Surveyor (if equipped with BP). Some facilities calibrate BP at sea level,
an elevation correction will need to be made.