Hach-Lange SD900 User Manual - Manual (Page 29)

The measurement status screen shows current measurement of each channel on the sonde which
includes the measurement name and unit assigned to each specific channel. The measurements will
be updated based on the user-defined scan interval. Navigation arrows on the screen indicate
whether additional channel information is available. CH0..CHX indicates the current position within
the available channels.
Volume calibration
The sample volume can be calibrated automatically with the liquid sensor or manually. When the
liquid sensor is used for volume calibration, the sensor is adjusted to accurately measure all
programmed volumes. If the liquid sensor is disabled, the volume for samples, rinses and stormwater
must be calibrated manually.
For typical applications, tap water can be used for the volume calibration. If the sample composition
is significantly different from typical water samples, calibrate the sampler with the liquid to be
collected. All programs must be stopped before calibration.
Calibrate the liquid sensor
The accuracy of the liquid sensor varies with the type of liquid that is sampled. For example, the
volume of a highly turbid sample may not be as accurate as that of clear water. The liquid sensor can
be calibrated with the sample water to improve volume accuracy.
1. Put the intake tubing into the sample water.
2. Push MENU.
3. Go to PROGRAM SETUP>MODIFY SELECTED>LIQUID SENSOR>ENABLE to make sure that
the liquid sensor is enabled.
4. Go to SYSTEM SETUP>LIQ SENSOR CAL.
5. Select PERFORM CAL.
6. Select START. The pump operates in reverse to purge the intake tube. The pump then operates
in the forward direction.
7. Look at the sample flow in the intake tube to make sure that the sample goes through the liquid
sensor.
8. When the sample goes through the liquid sensor and no bubbles are present, push STOP. The
intake tube is automatically purged. The liquid sensor calibration is complete.
9. Select DONE to exit or REPEAT to do the calibration again.
Restore the default calibration
The volume calibration for the liquid sensor can be returned to the default factory settings.
1. Select PROGRAM SETUP>MODIFY SELECTED>LIQUID SENSOR>ENABLE to make sure that
the liquid sensor is enabled.
2. Push VOLUME CALIBRATION and select RESET CAL. The volume calibration is set to the
default settings. The message “value has been reset to 0” will be shown.
Calibrate the sample volume with the liquid sensor
Calibrate the sample volume with the liquid sensor enabled to adjust sample volumes slightly.
1. Go to PROGRAM SETUP>MODIFY SELECTED>LIQUID SENSOR>ENABLE to make sure that
the liquid sensor is enabled.
2. Put the intake tubing into the sample water or tap water.
Note: Use the sample water for best accuracy.
3. Put the tubing from the outlet side of the pump into a graduated cylinder.
4. Push VOLUME CALIBRATION and select CALIBRATION.
5. Select START. The pump operates in reverse to purge the intake tube. The pump then operates
in the forward direction and collects the sample volume that is specified in the sampling program.
The pump operates in reverse to purge the intake tube.
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