Moisture determination guidelines

Our moisture determination guidelines can be used by producers and elevator operators who use one of these moisture meters:

• Model 1200A
• Model 919/3.5"
• Model 393/3.5"

The Canadian Grain Commission uses 2 models of moisture meters for official testing of grain samples:

• Seedburo Model 1200A moisture meter
  • Over 100 used at Canadian Grain Commission offices across Canada.
• Labtronics Model 919/3.5" moisture meter
  • Used at by Canadian Grain Commission staff when visiting off-site locations

The Canadian Grain Commission provides:

• Regressions equations for Model 1200A moisture meters
• Moisture conversion tables for Model 919/3.5" moisture meters

Note: Model 919/3.5" moisture conversion tables can be used for Model 393/3.5" moisture meters.

Verifying accuracy of moisture meters

Canadian Grain Commission moisture meters are checked for precision every 2 weeks. The Grain Research Laboratory at the Canadian Grain Commission maintains a check test system to ensure that all Canadian Grain Commission moisture meters operate within allowable tolerances of ± 0.2 percent moisture.

Check test samples are made available to all major grain companies so they may:

• Compare their standard meter results with Canadian Grain Commission moisture meter results.
• Use those standard meters to establish their own check test systems.

Before you begin moisture testing

• Ensure the sample is free of dockage.
• Ensure the temperature of the sample is between 11°C and 30°C.
• If you see moisture on the surface of the grain, leave it in a sealed plastic container at room temperature until the moisture has been absorbed into the grain.
• Ensure your scale is accurate, following Effectively using Model 919/3.5" moisture meters or Model 393/3.5" moisture meters.
• Ensure you use:
  • The correct regression for the Model 1200A moisture meter.
  • The correct conversion table for the Model 919/3.5" moisture meter.

Effectively using Model 919/3.5" moisture meters or Model 393/3.5" moisture meters

To effectively use Model 919/3.5" moisture meters or Model 393/3.5" moisture meters, follow these tips:

• Each day that you use your scale and thermometer, check them to verify their accuracy.
  • For scales, check using a set of weights or a sample of known weight.
  • For thermometers, ensure there are no separations in the mercury or alcohol columns.
• Determine the temperature of each sample and record it.
  • Test samples when their temperature is between 11°C and 30°C.
• Verify the calibration of the meter.
  • At least every 10 minutes during continuous use.
  • After each sample with intermittent use.
• Do 3 tests on each sample.

Maintaining accuracy of Model 919/3.5" moisture meters

• Avoid switching grain cells between moisture meters. A moisture meter cell and body are calibrated as a unit. Errors may occur if they are interchanged.
• Keep the test cell clean.
• Occasionally check the connection between the cell and the moisture meter. To do this:
  • Put the moisture meter in the CAL position.
  • Wiggle the test cell. If the moisture meter's needle moves sharply, 1 or both of the cell contacts need to be replaced. Refer to List of moisture meter service locations.
• Check the moisture meter's electronic alignment at least once a year. To do this:
  • Create 3 samples. On your moisture meter, each sample should give a different reading: approximately 75, 50 and 15.
  • Keep the sample temperature the same when testing the 2 moisture meters. Store samples in moisture-proof containers between tests.
  • Retest these samples on another moisture meter (preferably a Canadian Grain Commission moisture meter) to see if the results are similar.

Calibrating Model 919/3.5" moisture meters

How often you test samples influences how often you need to check the calibration of your moisture meter.

• If you are continuously testing samples, calibrate the moisture meter at least every 10 minutes.
• If you are intermittently testing samples, calibrate the moisture meter before testing each sample.

To calibrate a Model 919/3.5" moisture meter:

• Move the ON-OFF switch to ON.
• Turn the function knob to CAL.
• Turn the large knob on the moisture meter's right side until the dial reading 53 is directly beneath the hairline. Dial reading 53 has a red arrow marked CAL.
• Rotate the small knob on the moisture meter's left side until the meter needle reaches the lowest possible position on the meter movement.

Measuring temperature of grain samples

To measure the temperature of a grain sample:

• Use a sample of grain that has been weighed and cleaned.
• Place the sample in the warm-up container or dump cylinder.
• Insert a thermometer in the grain sample.
  Important: Make sure the thermometer's bulb does not touch the container walls.
• Wait 1 to 3 minutes to stabilize the thermometer.
• Record the temperature of the sample:
  • If the temperature is from 11°C to 30°C, determine the moisture content.
  • If the temperature is under 11°C or over 30°C, keep the sample in an airtight container until its temperature is from 11°C to 30°C.

Determining moisture content of grain samples

To determine the moisture content of grain samples:

• Read Before you begin moisture testing.
• Calibrate the moisture meter, if required. Refer to Calibrating Model 919/3.5" moisture meter.
• Set the function knob on the moisture meter to OP.
• Record the temperature of the grain. Refer to Measuring temperature of grain samples.

Taking a moisture content reading

To take a moisture content reading:

1. Place the loaded dump cylinder on the measuring cell.
2. Push the release button to dump the sample into the test cell.
   • Important: If grain contacts the surface of the centre post's inverted cone portion, the sample is probably lightweight. This means the moisture meter's reading will be inaccurate. Refer to Estimating moisture content for lightweight samples.
3. Remove the empty dump cylinder from the measuring cell.
4. Turn the dump cylinder over to prepare it for the next sample.
5. Turn the large knob on the meter's right side until the needle reaches the lowest position on the meter movement.
6. Record the dial reading directly beneath the hairline to the nearest 0.5 of a division.
7. Return the weighed grain sample to the dump cylinder. Make sure that you do not lose any kernels.
8. Repeat steps 5 to 8 twice to take a total of 3 meter readings.

Determining moisture content of grain

• Calculate the average of 3 meter readings.
• Look up the percentage moisture using the average dial reading and sample temperature on the conversion table for that grain.
• If the reading is higher than those on the conversion chart, refer to Estimating moisture content for high-moisture samples.

Estimating moisture content for lightweight grain samples

For lightweight CWRS, oats and barley

Regressions for lightweight CWRS, oats and barley are included on the Model 1200A moisture meter.

Use conversion tables to estimate moisture content for lightweight Canada Western Red Spring wheat, oats and barley samples. These tables are for use with Model 919/3.5" and Model 393/3.5"moisture meters. (Link to Conversion tables for use with model 919/3.5" and model 393/3.5" moisture meters.)

Weight at which grain is lightweight

Type of grain	Weight
Canada Western Red Spring (CWRS) wheat	Less than 66 kg/hL or 320 g/0.5L
Oats	Less than 48 kg/hL or 220 g/0.5L
Barley	Less than 52 kg/hL or 250 g/0.5L

Samples of wheat, oats and barley are considered lightweight if grain touches the surface of the inverted cone portion of the cell post in the measuring cell.

For lightweight wheat classes other than CWRS

These procedures are for estimating the moisture content of lightweight samples of the following wheat classes:

• Canada Western Soft White Spring (CWSWS)
• Canada Western Red Winter (CWRW)
• Canada Western Amber Durum (CWAD)
• Canada Western Extra Strong (CWES)
• Canada Prairie Spring Red (CPSR)
• Canada Prairie Spring White (CPSW)

To estimate moisture content:

Step number	Action	Example Using a 225 g-sample of lightweight CWSWS at 15°C
1	Test a 225-gram sample within the acceptable temperature range (11°C to 30°C). Refer to Procedures for determining moisture content.	Sample gives: a meter reading of 40.0 on a Model 919/3.5” moisture meter a direct moisture content reading of 16.2% on a Model 1200A moisture meter
2	Determine the moisture. For the Model 1200A moisture meter use – Red Spring Wheat, test weight less than 66 kg/hL - Table Number 9 For the Model 919/3.5” moisture meter use conversion table Number 9 – Red Spring Wheat, test weight less than 66 kg/hL	Conversion Table 9 – (CWRS, test weight less than 66 kg/hL) gives a moisture percentage of 16.2.
3	Subtract or add the correction factor. Refer to the Correction factors table.	The correction factor for CWSWS is -0.1. The corrected moisture for the lightweight sample is (16.2 – 0.1) or 16.1%.

Correction factors

Moisture range %	CWSWS	CWRW	CWAD	CWES	CPSR/CPSW	HWS
10.0 – 12.0	0.0	-0.1	-0.4	-0.2	0.2	-0.1
12.1 – 14.0	-0.1	-0.3	-0.6	-0.3	0.0	-0.1
14.1 – 16.0	-0.3	-0.5	-0.8	-0.4	-0.3	-0.1
16.1 – 18.0	-0.4	-0.6	-0.9	-0.5	-0.5	-0.2
18.1 – 20.0	-0.6	-0.8	-1.1	-0.6	-0.7	-0.2

Estimating moisture content for high-moisture samples

To estimate moisture content, if the meter reading on a sample is higher than those on the conversion table:

1. Accurately weigh out a portion of the original sample larger than is required for testing.
   • Example: Use 300 grams of red spring wheat, not 250 grams as required for meter testing.
2. Spread the sample on paper. Let the sample dry at room temperature.
3. Re-weigh the sample.
4. Calculate the percentage weight loss using this formula:
   • C = 100 (A - B) / A
   • A = Original sample weight
   • B = Sample weight after air drying
   • C = percentage of weight lost during air drying
5. Mix the sample thoroughly.
6. Weigh out a portion of the sample. Use the amount required for a moisture meter test.
7. Determine the temperature of the sample.
8. Follow Procedures for determining moisture content.
9. Determine the total moisture content of the sample using this formula:
   • E = [(100 - C) x (D/100)] + C
   • C = percentage of weight lost during air drying (found in Step 4)
   • D = Moisture content determined by the moisture meter (found in Step 8)
   • E = Total moisture content
10. Report the result to the nearest 0.1%.

Calculator for estimating moisture content for high-moisture samples

Estimating moisture content for beans with no conversion tables using the Model 919/3.5" moisture meter

The damp moisture range for beans is over 18%.

Important: Regressions for the bean classes listed here are included on the Model 1200A moisture meter.

Dutch brown beans

1. Use the Canadian Grain Commission Pea Bean Conversion Table Number 2.
2. Subtract 1.1 from the table result.

Great Northern white beans

1. Use the Canadian Grain Commission Pea Bean Conversion Table Number 2.
2. Subtract 1.4 from the table result.

Pink beans

1. Use the Canadian Grain Commission Pea Bean Conversion Table Number 2.
2. Subtract 1.1 from the table result.

Small red beans

1. Use a 250-gram sample.
2. Take a reading. Refer to Procedures for determining moisture content.
3. Apply the regression formula.
   • T = sample temperature in degrees Celsius
   • Percentage moisture = 0.155 x meter reading + 8.03 + [0.1 x (22-T)]

Otebo Beans

1. Use the Canadian Grain Commission Pea Bean Conversion Table Number 2.
2. Subtract 0.3 from the table result.

Kintoki Beans

1. Use the Dark Red Kidney Bean Conversion Table Number 2.
2. Read the percentage moisture directly from the table.

Example using Great Northern white beans

Use the Pea Bean Conversion Table Number 2. According to the conversion table, a 250-gram sample is required.

A sample of Great Northern white beans at 18°C gives a reading of 25 on a moisture meter. According to the conversion table, the moisture content of Pea beans is 13.6% for a reading of 25.

To adjust the moisture content for Great northern white beans subtract 1.4 from 13.6. The actual moisture content for Great Northern white beans is 12.2 percent.

Service for resolving moisture content disputes

You, a producer, or a person delivering grain for you may disagree with the moisture content received for a grain delivery at a licensed primary elevator. When this happens, you can ask the Canadian Grain Commission to determine the moisture content and make a binding decision. You are paid according to this decision.

This is part of a service referred to as Subject to Inspector's Grade and Dockage. It is a provision under the Canada Grain Act and Regulations.

How the service works for moisture content disputes only

1. Tell the primary elevator operator that you disagree with the moisture content assessed.
2. Ask the primary elevator operator to take a representative sample and to send it to the Canadian Grain Commission for an inspection Subject to Inspector's Grade and Dockage. A representative sample is one that both you and the primary elevator operator agree is representative of your entire load.
3. The primary elevator operator will:
   1. Place the 300 gram sample in an unbreakable container. Both you and the elevator operator must agree that the container will maintain the quality and moisture content of the grain sample. The container must be airtight.
   2. Label the container: Subject to Inspector's Grade and Dockage – moisture content only.
   3. Complete a Subject to inspector's grade and dockage – Western Canada – I-128 form.
   4. Send the complete form, along with the sample, to the nearest Canadian Grain Commission service centre.
   5. Give you an interim primary elevator receipt.

A Canadian Grain Commission inspector examines the portion, determines the moisture content, and sends the results to each person named in the request.

Contacts

• Determining moisture content contacts:
  • List of meter service locations
  • Moisture technician, Canadian Grain Commission
  • Inspection Services contacts