Calibration Consideration / Limits - AgraTronix MT-PRO+ Manuel De L'opérateur

CALIBRATION CONSIDERATION / LIMITS

Typically the moisture tester will be consistent
with most elevator testers over a broad range
of moisture levels. However, there are some
things to consider when thinking about your
moisture tester calibration.
NOTE: Graph 1 provided is for illustration purposes
only and does not reflect actual test data.
1. Tester Differences: Your moisture tester
unit may not match a given elevator tester.
None of the testers exactly match the
actual weighted moisture of any given
grain. There is no national standard for
elevator testers. The difference between
moisture testers and various U.S.D.A.
approved elevator testers is not a constant
value. A correction at one moisture level may
not be valid for a different moisture level.
Graph 1 illustrates how the moisture tester
might compare to an elevator tester over a
broad range of moisture levels. The moisture tester and most elevator testers
(shown in graph by solid line) will closely match those of the moisture tester
(shown by dashed line) for that range, as illustrated. However, as we get away
from mid-range into the high and low moisture levels, differences between
elevator tester and moisture tester not only become greater, but may switch
from a moisture tester reading higher than elevator tester to a reading lower
than the elevator tester. For example, in Graph 1, the area between B and C
represents the mid-range moisture. Moisture tester readings match elevator
tester readings in this area with an accuracy of plus or minus 0.5 percent.
The area between A and B represents the low moisture range. Moisture
tester readings differ more from elevator tester readings, and are LOWER
than elevator tester readings. The area between C and D represents the
high moisture range. Moisture tester readings again differ more from elevator
tester readings than they did at mid-range moisture, but now the readings are
HIGHER than elevator tester readings.
2. Calibration Requirements: Graph 1 illustrates that moisture tester readings
closely match elevator tester readings for mid-range moisture levels. (Graph
1 is for illustration purposes only and does not reflect actual test data.)
Calibration changes required for grain in this moisture range will be small,
if any. However, if grain is very dry (Low Moisture Range) or very wet (High
Moisture Range), it may be necessary to calibrate your moisture tester unit
against the elevator tester using a sample of your grain in both testers. Record
the calibration correction required. It will be valid for all testing in that moisture
range for that grain.
Operation
10-12
LOW MID
MOISTURE TESTER
ELEVATOR TESTER
GRAPH 1:
Moisture Tester - Elevator Tester
Comparison
HIGH