pH

  • Can I reuse my pH calibration solution

    No, evaporation and contamination quickly change the mix making your calibration inaccurate.
  • How do I know when to replace my pH probe?

    A failing pH probe will be slow to show a result and will be difficult to calibrate. A simple test can be performed using Windex glass cleaner with ammonia, and any type of soft drink. The procedure is as follows. Step 1: Turn your meter or tester on Step 2: Place the probe in a soft drink. ...
  • How long should a pH electrode last?

    Over time, all pH probes and electrodes deteriorate with use and age.  The average life span of any pH probe or electrode is typically 12 to 18 months, with proper storage and maintenance.  All Milwaukee Instrument’s probes and electrodes are covered under a 6 month warranty.
  • How often should I do pH Calibration?

    To be the most accurate, you should calibrate before each use. However, most units will hold calibration very well. If you are using your unit everyday, then check it once each day. If you get a reading that is above or below what you were expecting, then check the calibration at that point and r...
  • How to clean a pH electrode

    Residue from the sample can impact the sensitivity of the sensing bulb and clog the junction. This is especially true if the sample has a lot of organic material. Common signs that you need to clean the electrode are slow, drifting or erratic readings. You should proactively clean your pH electro...
  • What is a pH buffer?

    Some substances enable solutions to resist pH changes when an acid or base is added. Such substances are called buffers. Buffers are very important in helping organisms maintain a relatively constant pH.
  • What is Automatic Temperature Compensation (ATC)?

    pH readings vary with temperature. For example, a sample with a pH of 7 at 77 F Celsius will have a pH of 7.08 at 41 F and a pH of 6.98 at 140 F. You can either adjust for the difference manually or have the compensation adjustment made automatically by buying a pH meter with ATC. pH meters with ...
  • What is pH?

    The concentration of hydrogen ions is commonly expressed in terms of the pH scale. Low pH corresponds to high hydrogen ion concentration and vice versa. A substance that when added to water increases the concentration of hydrogen ions (while lowering the pH) is called an acid. A substance that re...
  • What is the advantage of a double junction electrode?

    A double junction electrode is less likely to become clogged because the second junction is located higher up in the probe out of contact with the sample.
  • What is the difference between one point and two point calibration?

    Single point is almost always done at the 7.0 position. Single point is fine as long as the area you are testing is within the neutral zone of 5.5 to 8.5. However, for accuracy in most applications, you need to have two point calibration. That is why most Milwaukee Instruments come with a 2 point...
  • What pH calibration solution should I use?

    In general terms, you should choose your calibration solution based on the expected pH of your sample. If you expect the pH of the sample to be 6 pH. Use pH 4.01 and 7.01 calibration solutions. If you expect the pH of the sample to be 8, the use 7.01 and 10.01. Check your manual for more informat...
  • Why are my pH readings inaccurate?

    Common reasons inaccurate pH reading include: A dirty pH probe preventing function An uncalibrated meter Damage to the glass sensing bulb in the pH probe (cracks can be hard to see) Damage to other parts of the electrode like the cable Try the following trouble shooting steps Step 1 Inspect t...
  • Why does my new pH probe have some type of salt around the cap?

    It is common to see salt build up around the probe when you receive your new meter, tester or pen. The salt is caused by the storage solution evaporating in transit. Just rinse the salt off and let the probe soak for an hour in 4.01 calibration solution or storage solution and then follow the cal...
  • Why should I use Storage Solution to store my pH probe or pen rather than water or DI water.

    MW9015 Storage Solution is the same chemical mix as the reference in Milwaukee pH probes meaning that reference will stay stable. Using storage solution is highly recommended and will help extend the life of your electrode. Storing in or hydrating a probe with tap water can alter or weaken the p...