I looked into this further and what you are seeing is normal. It turns out that there is an inverse relationship between temperature and pH.
It is also of interest that there are 2 different forms of temperature compensations to be considered. One, which we may be familiar with is commonly called ATC (automatic temperature compensation) of the pH probe junction. This addresses the temperature dependent flow of electrons from the pH probe junction (mentioned earlier in this thread). The 2nd form is the actual temperature of the liquid being measured. It turns out that this phenomenon is described by Le Chaterlier’s Principle. Science majors may remember hearing this in freshman inorganic chemistry.
The principle says that changes in temperature, pressure, volume, or concentration of a reacting system at equilibrium allow the system to change its state in order to nullify the effect of stress.
What that means here is, that when the temp in Justin’s system drops (even at the surface) the energy of atoms is decreased, thereby causing a corresponding increase in ionization to counteract the change. The effect is greater in alkaline conditions.
Not all ATC systems are reliable when working with temperature variant samples. Suitable pH electrodes for a particular temperature of the sample are to be employed.
* you may want to calibrate both pH & temp probes at the midrange temperature in your basement (ie ~69 deg F, between 60-78 F?)
It is also of interest that there are 2 different forms of temperature compensations to be considered. One, which we may be familiar with is commonly called ATC (automatic temperature compensation) of the pH probe junction. This addresses the temperature dependent flow of electrons from the pH probe junction (mentioned earlier in this thread). The 2nd form is the actual temperature of the liquid being measured. It turns out that this phenomenon is described by Le Chaterlier’s Principle. Science majors may remember hearing this in freshman inorganic chemistry.
The principle says that changes in temperature, pressure, volume, or concentration of a reacting system at equilibrium allow the system to change its state in order to nullify the effect of stress.
What that means here is, that when the temp in Justin’s system drops (even at the surface) the energy of atoms is decreased, thereby causing a corresponding increase in ionization to counteract the change. The effect is greater in alkaline conditions.
Conclusion: Does Temperature Affect pH?
Temperature impacts the pH of samples in two ways, either by affecting the electrode or by changing the nature of samples. Most of these effects can be eliminated using pH meters with built-in ATC systems.Not all ATC systems are reliable when working with temperature variant samples. Suitable pH electrodes for a particular temperature of the sample are to be employed.
Does Temperature Affect pH? - Techiescientist
The pH (pondus Hydrogenium) indicates the acidic or basic nature of a solution and is a measure of the number of free hydrogen ions present in an aqueous
techiescientist.com
* you may want to calibrate both pH & temp probes at the midrange temperature in your basement (ie ~69 deg F, between 60-78 F?)