I recently purchased model 100018 specifically to monitor 12VDC  battery voltage in an RV.  The voltage reading is critical-I’m using the meter to measure the percentage of charge.  The meter is reading .2 volts LOW.  I checked the voltage with two DVM’s.  Both DVM’s read exactly the same.  Can the meter be adjusted?  Otherwise, I would like a new meter, preferably one that is accurate.