pH meters & testers - ETI offer a wide range of pH meters and pH testers for a variety of applications. Our low cost pocket pH testers and portable pH meters are ideal for field based and laboratory pH testing. Click here to read our pH instrumentation guide!
ETI offers a comprehensive range of pH meters and testers. These instruments are designed as portable laboratory analysis testers for use in a wide range of industries. The pH (potential hydrogen) level of any material or substance is defined by the acidity or alkalinity of that substance and is represented on a scale of 0 to 14; 7 pH being neutral, 0 pH acidic and 14 pH alkaline. This factor can affect many parameters in nearly all types of process or production. We have a care & maintenace guide available by clicking here!
pH meters can be used in many areas, for example:
● food production
● water quality
● process industry
● fish farming
The pH (potential hydrogen) level of any material or substance is defined by the acidity or alkalinity of that substance and is represented on a scale of 0 to 14; 7pH being neutral, 0pH acidic and 14pH alkaline. This factor can affect many parameters in nearly all types of process or production.
maintaining your pH meter
If you do not look after your pH meter then incorrect measurements of pH levels may occur. As a minimum, you must always wash the pH electrode (the measuring part of the instrument) in clean water. Do not touch the pH electrode unless using a damp tissue or cloth for cleaning and then only using extreme care.
When not in use, ensure the pH meter electrode is kept moist in either storage solution or a pH 4 solution. If the sensor is allowed to dry out completely, the instrument’s performance will be effected and its warranty invalidated.
If an electrode has been allowed to dry out or becomes slow to respond, it may be rejuvenated by soaking the electrode overnight in storage solution. After overnight soaking, rinse the electrode and then soak in a 4 pH buffer solution before giving the electrode a final rinse. The electrode should then be ready for use.
calibrating your pH meter
To ensure accurate measurements, it is necessary to calibrate pH meters on a regular basis. For this you will require pH buffer solutions. These standard, inexpensive solutions are used to check that the pH reading is correct.
If it is not, it can be easily corrected following the procedure for the specific instrument. Generally pH electrodes have a limited working life, dependant on the frequency of use.
1. Q: How often do I need to calibrate my pH tester or meter?
A: Depending on the accuracy required, once a day if several measurements are required during the day; or at least once weekly if you use 2 or 3 times per week.
2. Q: Why does the pH tester or meter Display 1 or show erratic reading when power on?
A: When the electrode is held in the air and not dipped or in contact with a solution, it will display erratic readings. This is because the reference and glass electrode are in close contact, therefore the electronics cannot show a fixed reading. Dip the electrode into any solution and a reading will appear.
3. Q: Why does the pH tester or meter take sometime to get a stable reading?
A: Electrode was dry or not properly conditioned. Reference junction is possibly clogged up. Remedy: Pre-soak the electrode for 1 hour in tap water before using.
4. Q: How long will a pH tester last?
A: All pH glass electrode will age with time and temperature. Most glass electrodes have a storage life of about 1 year. A life-span of about 3 to 6 months for frequent/continuous use.
5. Q: What other problems are associated with measurement?
A: Temperature is important as liquid properties are affected. Therefore, a correct temperature of 25 °C for Buffer Solutions should be maintained during calibration. However correction of values may be made if the temperature of the solution is known, by comparing with the table below. Different temperatures of test samples will give inconsistent results.