[blatz]

Is there a more user friendly (i.e. moron proof) pH meter out there?  I seem to not be that good at calibrating and getting good readings.

Currently use a MW102.

[kramerog]

Difficulty in calibration could be an indication that the probe of the pH meter is not working.  That could happen because it was not properly stored, the probe is going bad, etc. 

[mabrungard]

I have to wonder about some meters using computerized components on what amounts to a VERY analog instrument. While those features might make some aspects of pH meter use easier, I'm guessing that they can also create havoc.

I've used the MW-101 for about 6 years now and its been very reliable. Totally analog instrument.

[neddles]

I've used the MW-101 for about 6 years now and its been very reliable. Totally analog instrument.

Same here. 3yrs on my MW-101. No complaints, easy to calibrate and stays well calibrated a long time.

[pfabsits]

Is there a more user friendly (i.e. moron proof) pH meter out there?  I seem to not be that good at calibrating and getting good readings.

Currently use a MW102.

I am to sure if you will find an easier to use meter.  The MW102 has automatic calibration which will present problems when the probe need to be cleaned or changed. Being auto-calibration, the meter will be looking for a specific voltage window for offset (pH 7.01 calibration) and for slope (Change from pH 7 to pH 4). If the right voltage is not generated then the meter will not calibrate. In a way this is a good thing since if the probe is too far out of specification then it should not be used. A qucik way to check is to pull the battery from the meter to clear the calibration. The place the probe in pH 7 buffer. If the value is below pH 6 or above pH 8 then the meter will not calibrate since the offset is greater than 60 mV (1 pH unit). At that point you can try cleaning the probe to see if it is the cause of the offset error.

Another challenge with automatic calibration is that the meter looks for stability before locking on the reading and allowing you to confirm the value. If the reading is drifting and there is no stability then the "cfm" will not be displayed.

Drifting readings are a sing of a dirty electrode or clogged junction.

Those are the main problems for meters with automatic calibration. It is possible to buy a meter with manual calibration in which there are trimmers used to adjust pH 7 and pH 4/10 buffers. They do not rely on stability but will have the same limitation in offset/slope acceptance. That is if on a default cal (short BNC connector to adjust to 7.0) the pH reading of the probe in buffer will still only allow +/-1 pH unit. So any reading of the pH probe in pH 7 buffer greater than pH 8 or less than 6 will not be adjusted to pH 7.0. There is not enough span to do so.

A couple of final points:
* pH electrodes last about 1-2 years. If you can check offset and slope then the probe can be used as long as the offset +/- 30 mV and slope >90%. Meters calibrate to +/- 60 mV and slope >85%.

* When not using the probe store it in storage solution. If you do not have storage solution then use pH 4. Lower pH's inhibit microbial growth.

* Rinse the electrode with purified water before calibration, before use, and after use. Aquafina is purified by RO so it is pretty clean. Other bottled water can be purified by RO but some companies add minerals back in for taste. I would not use this water for rinsing the electrode. Distilled water is also available at the local grocery store.

* Use fresh buffers. If you only use the meter periodically (i.e. 1/week, 1/month)then use buffers in packets. Use the packet once and dispose. If using daily then a jar can be used for calibration buffer that is replaced every 3-4 days with fresh solution. Never pour pH buffer back into the bottle that it is supplied with.