Measuring - wtw SenTix FET-D Bedienungsanleitung

Measuring / operation
Instructions on
measurement
Instructions on
measurement
32
4.6

Measuring

Observe the required depth of immersion (see chapter 7 T
l Prior to every measurement, thoroughly rinse the measuring tip with
deionized water and shake off the water.
l For precise measurements in liquids, attach the light shield to the
measuring tip.
l Press the On/Off key to switch on the sensor. The measuring LED flashes.
l Liquid measuring media: Immerse the sensor in the sample. When doing
so, the pH sensitive area and junction must be completely submersed in
the solution. If necessary, slightly move the sensor in the solution to
remove air bubbles in the vicinity of the junction and pH sensitive area.
l Solid measuring media: Slowly press the measuring tip into the sample.
When doing so make sure the pH sensitive area comes into contact with
the sample. Do not bend or twist the sensor when doing so to avoid
malfunctions.
l Measure the sample according to the operating manual of the used meter.
Warning
After measurement, do not eat food that was measured, not even partly,
as during measurement noxious substances can pass from the sensor
to the sample.
Warning
Avoid to use the sensor in acidic or alkaline media of 0.01 mol/l or more
for longer periods of time. This could shorten the lifetime of the sensor.
Note
In order not to affect the measuring accuracy, do not expose the sensor to
strong sunlight or other light during calibration or measurement.
l Standard solutions for calibration and test samples should have the same
temperature. Temperatures that diverge from each other cause a greater
measurement uncertainty.
l Calibrate the sensor before each series of measurements.
l After longer periods of nonuse (one week or longer), water the sensor in
3 mol/l KCl solution or pH 7 buffer solution for at least 30 minutes.
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SenTix FET-D/B
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ECHNICAL DATA