DIAGNOSTICS (CALIBRATION MENU: DIAG)
The diagnostic mode is an advanced mode that one can use to restore scale calibration and
read the raw scale output in mV/V (millivolt per volt).
Scale mV/V signal (one for each active channel)
This displays the scale mV/V signal (terS & -S) for each
channel. The normal range for an empty scale is from -0.1mV/V to
0.5mV/V. However, if there is a vessel, tank, etc. (with no product)
attached or sitting on the scale, this value can be higher than
0.1mV/V. The nominal range with product on the scale is from 0.2mV/V to 3mV/V.
A DMM measuring the actual mV at the signal terminals would read about five times the
value read here (e.g., a 1mV/V SCL1 screen display would show as 5mV on a DMM).
DIAGNOSTIC CALIBRATION READ/ENTRY
The following parameters allow one to read and re-enter calibration zero and span. These
parameters are used for an approximate calibration if one does not have test weights or the
ability to remove the weight from the scale. Entering these values, if calculated and entered
correctly, will yield a 0.25% or better calibration for each channel.
In order to use these parameters, the scale mV/V at a specific lb/kg weight (e.g., 3mV/V at
4000lbs) must be known - this is the “(scale) FULL SCALE” entry that’s written on the EI’
routing sheet.
Scale calibration dead-zero (one for each active channel)
The scale mV/V dead-zero value represents the weight of the
platform and, possibly, a fixed tank. NOTE: This value does not
include the weight a removable
SCL1 mV/V 0.0012
NXT LAST ESC
cylinder or tank. Any PTZ/AZ
values are not added to the zero value displayed. Press ADJ to adjust this value.
[FS mV/V]
DEAD ZERO
= ------------------------- x [Assumed dead weight WT (lb/kg)]
[FS WT (lb/kg)]
Scale calibration span (one for each active channel)
Scale calibration value, this is the load that is typically removable that includes the weight of
the product and container combined. Use the formula below to
calculate an approximate calibration factor that’s entered into this
parameter. To shift the decimal point, press the DP pushbutton.
[FS WT (
lb only!
)] [FS WT (kg) X 2.2046]
CAL
= ------------------------- = --------------------------------
[FS mV/V] [FS mV/V]
Note: If the full scale weight is in kilograms (kg), multiply the weight by 2.2046 and then divide it by the
full scale mV/V value.
ZERO1 CAL 0.002
NXT LAST ADJ ESC
Example: If the scale full-scale is 3mV/V @ 4000lbs and the assumed dead weight is 500lbs, the value one would enter
into the dead zero value parameter is 0.3750.
SPAN1 CAL 416.67
NXT LAST ADJ ESC
Example: If the scale full-scale is
3mV/V @ 4000lbs, the CAL
value entered is 1333.3.