Montomco Moisture Meter Model 919

[Briercrest]

We have a MONTOMCO grain testing moisture meter - Model 919 that seems to be out of wack on it's readings. Even after recalibration is done - it still is about 1.4 out compared to our local elevator read out. There is an adjusting bolt without a knob on the calibration adjustment side which I believe to be what I need to turn. One might assume that an up turn of the bolt would be to increase and down turn would decrease the calibration setting. Anyone out there who has been gutsy enough to try this out?
Willo of Saskatchewan