Hydronix Hydro-Probe XT, User Manual

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Chapter 5 Sensor Integration and Calibration
48 Hydro-Probe XT User Guide HD0538 Rev: 1.6.0
2.4.3 Procedure (Using Hydro-Com Software)
1. Ensure Hydro-Com is running with the calibration page open.
2. Create a new calibration by entering a Calibration name and clicking “Next”..
3. When collecting a sample the Average/Hold status next to the ‘Average Unscaled’
reading from the sensor should read ‘Averaging’ in green. When not sampling it
should read ‘Hold’. The optimum installation is one where the digital input is wired
into the bin-gate switch or a switch local to the sampling point.
4. When taking a sample in a batch system collect at least 10 small samples over the
course of the batch from the flow to yield a bulk sample of around 4-5Kg of material.
The material MUST be collected at a position close to the sensor and therefore the
sensor reading relates to the particular batch of material passing the sensor.
5. When taking a sample in a continuous process the digital input should be wired to a
switch local to the sampling point. When collecting the sample the operator should
activate the switch and when the operator has finished collecting the sample the
switch should be deactivated. Collect around 4-5Kg of material in a bucket.
6. Mix the material and place in an air tight container. If the sample is hot it should be
allowed to cool to room temperature and then any condensate moisture should be
mixed back in to the sample.
7. Remove a representative sub-sample of at least 10 smaller increments to yield
approximately 1 kg. Dry it thoroughly and calculate the moisture content using the
moisture calculator. Take care not to lose any of the samples during the drying
process. A good test to ensure the material is thoroughly dry is to stir it around to
distribute the moisture and reheat.
8. Return to the computer and record the ‘Average Unscaled’ output, which should show
the ‘Hold’ status. Click “Add Point” to add the Average Unscaled value to the
calibration table.
9. Repeat step 7 for at least 2 more 1Kg representative sub-samples. If the moistures
differ by more than 0.3% then one of the samples was not dried out completely and
the test has to be restarted.
10. Record the Average Moisture of the three samples in the calibration table. The
‘Moisture’ and ‘Average Unscaled’ values make up one calibration point. Tick this
point to include the values in the calibration.
11. Repeat steps 5 – 9 for additional calibration points. Choose a different time of day or
different time of the year to ensure a wide range of moistures are samples.
A good calibration is one where the calibration points cover the complete working
moisture range of the material, and all points lie on, or near to, a straight line. If any
calibration points are suspected to be wrong, then they can be excluded from
calibration by deselecting their corresponding tick box. It is generally recommended
that a spread of at least 3% will give the best results.
When the calibration is finished, update the new calibration coefficients to the correct
sensor by pressing the ‘Write to Sensor’ button. The B, C and SSD values in the sensor
frame will then match those values in the calibration frame. The moisture % output from
the sensor should represent true moisture of the material. This can be verified by taking
further samples and checking the laboratory moisture against the sensor output.