With a waterproof casing, LCD display and small size this PH meter is a doddle to use. Low power consumption, will power off after 10 minutes of inactivity. Automatic temperature compensation with temperature display. Plastic storage case and English instructions are included.
pH Measurement Range: 0-14pH
Temperature Measurement Range: 0.0~50.0° (32~122°)
C & F display
The Automatic Temperature Compensation (0.0~50.0°)
Includes 3 sachets of buffer solution at different PH levels.
One of our customers, Mr Martin Farrimond has very helpfully rewritten the instructions, see below:-
“HODE” -> Hold
ON/OFF: [Short] Press to switch on/off
HOLD: [Short] press to hold/freeze the reading. Short press again to unhold. In Hold mode, the decimal point stops blinking.
CAL: Calibration and temp units change.
Temp units selection:
Choice of °C or °F. Should be supplied with default to °C. To change units…
With the meter switched off, press & hold the “CAL” button, then press the ON/OFF button until the display becomes active, then release both buttons. The display blanks, showing only the temp unit selected in the bottom right. To change the units, briefly press the “CAL” button. Each press will switch between °C and °F. To select the temp unit, press the “HOLD” button. The display should briefly display “SA”, your selected temp unit will be stored and the display should show the temperature.
In normal use, the decimal point will blink once per second.
Prior to first use and from time to time, you should calibrate the pH meter.
[I think] that before using, it suggests immersing the pH meter probe (the glass bead) in distilled water for 10 mins.
To measure, ensure the glass bead and the metal temp probes are both fully immersed in the liquid [to a mx depth of 15mm]. Leave until the pH reading stabilises. Seemples.
To lock the reading, briefly press the “HOLD” button. Press the “HOLD” button once more to unlock the reading.
After use, before storing, rinse the probe in clean, ideally distilled, water and dry carefully with lint-free cloth. Be careful as the glass bead is delicate.
You need three buffer solutions: one packet of each of these should have been provided with the meter when new. Each pack can be used to make 250ml of buffer solution. Hint: buy, or save from your recycling, 3 x 250ml plastic or glass bottles! Further packs are readily available (e.g. ebay). Ideally, use a glass stirrer to help dissolve the powder (metal ones might affect the pH of the buffer test solution).
The three buffer solutions needed are pH6.86; pH4.01; and pH9.18. Make these up according to the instructions on the packets.
The meter should be calibrated with the buffer solutions at 25°C. This is important.
Fully immerse the probe in 10-15mm depth in the pH6.86 solution at 25°C. Leave until the reading stabilises, then press the “CAL” key for 3 seconds. The display will briefly show 6.86, then “SA”, then “End”.
Repeat this for the pH4.01 and pH9.18 solutions respectively. (The meter automagically recognises which PH level you’re calibrating).
It is suggested you discard used buffer solution.
Don’t immerse the probes too deep into liquid: you only need about 10 – 15mm depth of liquid.
Don’t allow liquid up into the instrument.
The probes, i.e. the bottom end of the instrument, can be unscrewed and removed – presumably to facilitate replacement, but I haven’t found any suitable replacements available.
The batteries are hidden inside the top of the instrument, which also unscrews. These are LR44 (or equivalent) and there are four of them. They are a bit of a bitch to replace and it looks like it would be all too easy to break the tiny wires soldered to the end connectors.
If the battery voltage drops lower than 3.7V, the display will blank, and [I think] the decimal point may blink [or possibly the whole display. Who knows?]. All four batteries should be replaced – don’t mix old and new.
The meter should automatically power off after 12 minutes
I hope that helps some folk!