Measuring The Ph Value; Measuring Soil Solution Ph Value - bluelab Multimedia pHMeter Care And Use Manual

5.0

Measuring the pH value

Once the Bluelab
a pH value involves using the Bluelab
button functions. NOTE: The pH probe tip must not have dried out. If it has dried, soak the
Bluelab ® Leap™ pH Probe in KCl for at least one hour prior to taking a measurement.
If measuring outside of solution, rockwool or small/shallow pots, remove the top
1
5cm / 2in. from the surface of the sample area.
If the soil/media is dry, moisten with a small amount of distilled water.
2
Turn the Multimedia pH Meter on.
3
Remove the storage cap and insert the Leap™ pH Probe in grow media, if using dibber
4
ensure probe in in contact with soil
Wait for the reading displayed on the Multimedia pH Meter to stablize to a constant value.
5
This can take up to four minutes. Record the reading.
Remove the Leap™ pH Probe from the soil/media and wash the Leap™ pH Probe tip
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under fresh running water (not distilled) to remove any remaining soil residue.
Repeat the procedure in different locations and take the average of the measured data as
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the pH level is representative of the sample area.
If the Multimedia pH Meter turns off while taking a measurement, simply press the power
8
button to turn the Multimedia pH Meter back on and continue with your measurement.
Store the Leap™ pH Probe between measurements. See section 10.0.
9
6.0

Measuring soil solution pH value

The greatest source of error in soil analysis comes during sample collection. An effort should be
made to ensure each sample properly represents the area being sampled.
• The readings taken with this method could be higher than those taken by other methods
• Consistency of the method used is important to be able to compare sets of results
• The accuracy of this method cannot be guaranteed because of the variables involved
• The results should be viewed as 'indicative' rather than 'absolute'
Collection of sample
Sample in a zig-zag pattern across the required area.
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Remove 15 mm / 5/8 in. of top soil before sampling at a depth of 150 mm / 6 in.
2
Mix all collected samples together thoroughly.
3
Allow to dry in the air or in an oven at 40 °C / 104 °F.
4
Weigh out 20 g / 0.7 oz of the collected soil into a 150 ml / 5 fl oz plastic sample jar.
5
Sample preparation
Add 100 ml / 3 fl oz of distilled or deionized water, screw lid on tightly.
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Shake continuously for 5 minutes. Leave overnight and shake again the next morning.
2
Allow to settle for 15 minutes after shaking and strain sample into clean measuring cup.
3
Take pH readings as follows:
Remove the storage cap and insert the Leap™ pH Probe tip into the soil solution sample.
1 1
Turn the Multimedia pH Meter on.
2
Wait for the reading displayed on the Multimedia pH Meter to stablize to a constant value.
3
This can take up to four minutes. Record the reading.
Remove the Leap™ pH Probe from the soil solution and wash the Leap™ pH Probe tip
4
under fresh running water (not distilled) to remove any possible soil residue.
If the Multimedia pH Meter turns off while taking a measurement, simply press the power
5
button to turn the Multimedia pH Meter back on and continue with your measurement.
Store Leap™ pH Probe between measurements
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See section 10.0.
1
Multimedia pH Meter has been set up and calibrated, using it to measure
®
Leap™ pH Probe, the dibber/auger for coarse soil and
®