ᐅ Measuring Residual Moisture in Screed Correctly Using the Trotec BM31

Hello,

I purchased the Trotec BM31 to measure residual moisture. However, I am unsure how to interpret the displayed value and whether I can start installing the vinyl flooring. The device shows 48 digits.

I have attached an excerpt from the user manual. According to the scale, 48 means dry.

But what do the values below in the table represent?

I would really appreciate it if someone could help me.

Thank you very much.

These are comparative values from measuring devices that make the results reasonable and meaningful.

As the manufacturer of your device already states:

Preliminary testing of building materials’ readiness for use during CM measurements.

Unfortunately, your value should actually only be seen as an indicator (for example, whether it is worth carrying out the CM measurement).

And the device is not calibrated either.

Only with a proper CM measurement can you perform a depth measurement in the screed, and the sample quantity (50g to 100g) also makes the result meaningful.

From my point of view, the only thing you can do with this device is determine that one spot is drier or wetter on the surface compared to another. Nothing more.

I also purchased the device to roughly assess the residual moisture of the screed. This works quite well... we are currently at the peak of the screed drying schedule and measuring around 60 digits at the lighter spots. Unfortunately, our anhydrite screed also has many sinter areas... in these spots, the value is still above 80!

This is already causing me some concern, as sanding will only be done when the tiler arrives... which doesn't really make much sense, since not much is likely to change in the sinter areas by then, right?