How to calibrate a pH meter?

How to calibrate a pH meter?

Calibrating a pH meter is necessary to ensure the pH meter keeps measuring accurately. When you calibrate a pH meter you need to have a special pH buffer solution or pH Calibration solution. This is a special pH Buffer designed to have a fixed pH level. For example, a pH buffer of pH 7.00 will have a fixed pH of 7.00. So if we insert our pH meter in this buffer solution, we should read a pH of 7.00 on our display. If the value measured by your pH meter does not correspond with the pH value of your pH buffer, you need to calibrate your pH meter. 

When you want to calibrate a pH meter correctly, always follow the instructions of your manufacturer. You can find the instructions on how to calibrate our pH meters right here. 

Do you want to buy pH buffer solution? Order our professional pH buffer solution on sale today!

How to calibrate a pH meter manually? 

Calibrating a pH meter manually is very easy. Before you start the calibration process, make sure you have prepared a small cup with pH buffer solution. And nobody does this, but please read the manual of your pH meter. 

  1. Prepare a clean cup with pH buffer solution (for example pH buffer pH 7.00)
  2. Make sure the pH meter is clean and place it into the buffer solution.
  3. Stir gently and wait for 30 seconds. Wait until the measurement on your pH meter has completely stabilized. 
  4. Stir gently again and repeat step 3. 
  5. Either confirm the pH value with a button, or use the micro-screwdriver to adjust the pH level on the display so it matches the pH level of the pH buffer solution. 
  6. Clean the electrode of the pH meter in a neutral solution. 
  7. Your pH meter is now perfectly calibrated manually.

 

How to calibrate a pH meter automatically?

Automatically calibrating a pH meter is as easy as following the steps of the instructions provided with our pH meter or available here online. Automatic calibration usually requires 2 or 3 PH buffer solutions. So make sure you have these ready when you are starting the calibration process. When you need multiple pH buffer solutions, always start with the lowest pH value. 

  1. Prepare 2 or 3 clean cups with pH buffer solution (for example pH buffer pH 4.00) and 1 cup with a neutral solution. 
  2. Make sure the pH meter is clean and place it into the buffer solution nr 1.
  3. Stir gently and wait for 30 seconds. Wait until the measurement on your pH meter has completely stabilized. 
  4. Stir gently again and repeat step 3. 
  5. Now you press the calibration button and the pH meter will automatically detect the pH buffer solution and calibrate itself.
  6. Clean the electrode in the neutral solution.
  7. Repeat the steps 3 to 6 with the other pH buffers. 
  8. Your pH meter is now perfectly calibrated automatically.

The process of automatic calibration can be different depending on the manufacturer. Always use the instructions provided by the manufacturer.

How often do you calibrate a pH meter?

How often you need to calibrate your pH meter depends on the accuracy  required. The easiest way to tell if your pH meter requires calibration is to place it into a pH buffer solution and see if there is a difference between the pH level measured and the pH level of the pH buffer solution. 

If there is a difference, you need to calibrate your pH meter. 

When do you calibrate a pH meter? 

You calibrate your pH meter every time you need the most accurate pH measurement. There really is no definite answer for this. In laboratories it is normal to calibrate your pH meter every single day. But for applications where less precision is required, once per week or once per month could be enough. 

The most important thing to remember is to use high quality pH buffer solutions. We highly recommend using our Professional pH buffer solution. Our buffer solutions are NIST certified and produced according to the highest standards in the industry. You can find our range of pH Buffer Solutions here.

Remember that pH has a logarithmic scale. A pH level of 6 is 10 times more acidic than a pH level of 7. A pH level of 5 is 100 times more acidic than 7. 

Click here to find out more about what is pH.

PH Meter won't calibrate?

If your pH meter does not calibrate anymore, it is probably used and worn. A pH meter is filled with a reference liquid, over time this liquid loses its efficiency and just like a battery it slowly stops working. This is very normal and will happen to all non-fillable pH meters and pH electrodes. 

Try putting the pH meter or pH electrode in a KCI solution for electrodes for 24 hours. Sometimes this will help you to get a few more readings out of your pH meter. But eventually you will have to replace your pH meter. 

Is calibrating on 2 points more accurate?

Yes, calibrating on 2 or 3 points is always more accurate. That is why it is often a feature found on more expensive pH meters. It also requires you to buy more pH buffer solutions and is therefore only recommended for professional users or users who require a very accurate pH measurement.

This does not mean that pH meters with single point calibration are less accurate or of less quality. But it does compromise the quality of the pH measurement. 

Meterdiscount only sells pH meters that can be calibrated automatically on 2 or 3 points.Discover our range of accurate pH meters right here and order your pH meter today.