Moisture Curve Calibration; Prepare Samples - Juniper HarvestMaster GRAINGAGE H2 STATIONARY User Manual

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H2 Stationary GrainGage User's Guide

4 .2 Moisture Curve Calibration

CAUTION: Do not re-wet grain samples. If you need to adjust the moisture content, take a natural

sample and dry it down.

Before harvesting, you need to generate a chamber calibration (moisture curve). Chamber calibrations align

the moisture reading with a benchtop lab sensor.

For better accuracy, the practices in this guide are designed to streamline the calibration process and teach

users how to create moisture curves.

Preparing your samples is a critical first step towards creating and maintaining an effective moisture curve.

Step 1: Plan ahead for calibration. Creating an accurate moisture curve requires using grain samples with

a range of moisture percentages. Collecting enough samples to calibrate properly requires some advanced

planning. HarvestMaster recommends two separate strategies: planting grain varieties that will be available for

harvest before test plots are ready or harvesting border plots early and drying them to varying moistures.

Step 2: Imitate harvest conditions. When calibrating, it is recommended that you imitate harvest conditions

as close as possible. This means the grain has enough time to equilibrate to ambient outdoor temperature

before calibrating. The grain should be cycled through the hopper to reduce grain packing differences.

HarvestMaster recommends cycling samples 3–5 times each in both the benchtop sensor and the GrainGage

and then averaging the moisture readings. When possible, grain samples should be tested in the lab and in

the GrainGage within an hour of each other.

Step 3: Collect and prepare samples. Your challenge is to create a moisture curve that is representative of the

moisture range that will be encountered during harvest. The more samples available during calibration, the

more accurate the curve will be. HarvestMaster recommends:

• Using a minimum of three samples to generate a curve. The more samples the better.

• Each sample should be at least 6 pounds.

• At least a 3% moisture range from lowest moisture to highest moisture.

• The more samples within about a 10% range the better, but two or three samples will suffice.

Step 4: Adjust for high moisture corn harvest. If you have high moisture samples, HarvestMaster

recommends initially calibrating with samples below 26% to set the curve and then manually calibrating the

curve above 26% for the high moisture samples. A split curve will generate better data than an average curve.

Step 5: Position a bucket or bin under the GrainGage to catch grain samples. Ensure the bucket or bin is at

least 12 in (30.5 cm) tall, 15 in (38 cm) wide, and 15 in (38 cm) deep.

Step 6: Annually check and tune moisture curves. Checking and tuning moisture curves each season will

give you the best data quality.

H2 Stationary GrainGage Calibration

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