In today’s age, we rely heavily on processes that are “automatic”. Automatic processes simplify tasks and ensure we are on time and accurate. For example, it’s hard to imagine life without automatic bill payments or automatic settings for my thermostat in my home. I have no doubt, I would miss payment dates and my utility bills would certainly increase! Luckily for users of pH measuring equipment, you can set the calibration process to automatic mode, ensuring precise results.
Temperature’s Effect on pH Calibrations
pH calibration is typically performed using two or more solutions which carry a certified known value. These solutions, known as “buffers”, are heavily dependent on temperature. A look at the table below will show just how much temperature affects a pH buffer.
I have witnessed many pH calibrations in the field. Typically the procedure is to dip the pH sensor in the first buffer solution (commonly pH 7.00), let the measurement stabilize, and manually input the value of that buffer. Operators often mistakenly input the pH value displayed on the buffer bottle with little regard for the temperature on the pH meter. Consequently, disregarding the true pH value of the buffer solution at the given temperature will lead to inaccurate measurements!
Automatic Calibrations
Automatic pH calibration mode — known as Calimatic®mode in Knick transmitters and portable meters, compensates for the temperature of the buffer every time. This leads to accurate calibrations and thus accurate online measurements!
The Calimatic feature enables the selection of one of 11 of the most common buffer sets on the market with the temperature tables pre-programmed into the meter. More so, operators can even input their own table if using unique buffer solutions. Automatic buffer recognition simplifies the calibration process by identifying the buffer that the sensor is in and precisely compensating for the temperature of that buffer.
In conclusion, An accurate online measurement is heavily dependent on an accurate and precise calibration of the sensor. Utilizing Calimatic, automatic calibration, will guarantee proper temperature compensating during calibration and therefore ensuring the best results for your measurements!
