The Forestry Forum

I operate a Nyle L53 Kiln, when checking the load on a daily basis i use my pinless wagner MM to check MC. Because I am inside the kiln (usually running around 120 degrees or higher) will that effect the reading of the meter? I have noticed a different reading on boards on the last day of drying versus when they come out of the kiln,

My Wagner does not call for a temperature correction.  The Delmhorst J-2000X does require a temperature correction. 

Are your boards reading higher or lower the next day?  I was told to let the boards cool down and age "like a good steak" and then check the actual MC.  I use a Lignomat pinless and notice that the MC is lower after cooling.  

When you check lumber in the kiln during drying, it has a moisture gradient with the core being wetter than the shell.  So, the high core MC has more dominant effect.  Second, the meter is initially cool...cooler than the dew point... so condensation forms on the meter and gets into the electronics.  Neither a pin or pinless meter is designed to work with c0ndensation issues, so warm it up in a plastic bag before using it.  Third, the meter is calibrated for use at room temperature.  I have seen no indication that the meter itself is NOT affect by temperature; I have not seen where the manufacturer suggests that using a meter at 130 F or other temperature is ok...it is not.  So, I do believe a pinless meter should not be used on lumber with a gradient or used above room temperature (so, take the pieces out of the kiln for a minute at most).  A pin meter has the same equipment limitations, but at least Delmhorst and has wired systems and Lignomat has wireless probes that let the pins be in the kiln, but the measuring equipment is in a warm room.