Performance and conductivity of the coolant

How good is the coolant used and which values can be sensibly measured?

In the case of the cooling liquids from our Protect family, the concentration and the pH value are the decisive factors in determining the quality and performance of the cooling liquid (in use).

In principle, all cooling liquids lose part of their performance over time, which is why - depending on the quality and concentration of the cooling liquid used - the cooling liquid should also be checked at regular intervals. The coolants from the Protect family can usually be used in a closed cooling circuit for two years without any problems without the concentration or pH dropping to a critical value.

Measurement of pH

The easiest and fastest way to measure the pH is because all you need is a suitable pH test strip. In our online shop we offer this in a storage box with 100 test strips including a color scale. For the measurement, the colored end of a pH test strip is dipped into the cooling liquid, in order to then read off the color of the test strip with the printed color scale on the packaging included in the scope of delivery.

Swirl pH test strips in coolant

Compare the pH test strips with the pH scale

Examination of concentration

The concentration of the cooling liquid is checked using a high-quality refractometer. For this purpose, a few drops of the cooling liquid to be tested are placed on the prism surface and the refractrometer is held in the direction of a light source. The Brix value to be read now indicates the concentration in percent.

In the event of a measurable loss of concentration and corrosion protection (pH value), for example, the performance can be increased again by topping up with concentrate. If the pH value is below 8, however, the coolant should be completely replaced. Such an exchange also offers the advantage that it removes suspended matter and deposits contained in the circuit.

The concentration is determined with a refractometer

Tip: Before refilling, the cooling circuit should be rinsed with tap water in order to remove all residues of old coolant and deposits before filling the new coolant from the circuit.

Determination of a conductivity

On the other hand, it does not make sense to try to determine a conductivity, since our Protect coolants prevent electrochemical corrosion and thus actively suppress the corrosion current. Because of this, the conductance would change and decrease continuously in the event of a measurement. The suppression of the corrosion current is achieved through the accumulation of the inhibitors contained on the metallic components in the cooling system. This effect usually takes some time, which results in the continuous lowering of the conductance. This accumulation also occurs on the electrodes of the conductivity measuring device during a measurement. Monitoring and measurement of the conductance is therefore not necessary.