IRRI Moisture Meter


We stopped producing the IRRI moisture tester. We had transferred the technology to several small electronics manufacturers in Myanmar, Philippines and Cambodia and they made some units. However, these manufacturers relied exclusively on IRRI for orders and did not market the moisture meter themselves. The cost of manufacturing was therefore high. In order to be competitive our target was US$ 30 or less, however, actual cost was more than US$ 75. For around US$ 150 you can already get a commercial digital moisture with digital display and multi grain capacity. We had also talked to some larger manufacturers to get to the numbers that would result in low cost, but they were usually afraid that a low-cost moisture tester would reduce the sales of their more expensive units. 
Feedback from our projects in which we used the IRRI moisture tester indicated that there would be a market for a very low cost moisture tester.

postharvest-moisture-meterThe IRRI low-cost moisture meter for paddy

Although the resistance type moisture meters are not too expensive, farmers still cannot afford them. The IRRI low-cost moisture meter is a decision making tool for postharvest operations that costs half of the price of a more advanced moisture meter. It is designed as a decision-making tool in postharvest operations of paddy and is not intended for trade.

Typical applications are:

  • Checking whether paddy in a dryer or in sun-drying is dry enough to stop the drying process
  • Checking whether paddy intended for milling can be stored safely
  • Checking whether rice seeds are dry enough to be stored safely. Especially when storing seeds in the hermetic storage systems it is recommended to use either this or any other moisture tester to determine the seed moisture content before sealing the storage container.

The IRRI moisture meter is used as any other resistance type moisture meters by crushing a small sample of grains.

moisture-testerThree light emitting diodes (LEDs) and a beeper visualize the results.

  • Red – paddy is wet and needs to be dried (above 14%)
  • Green – paddy is dry enough for safe storage and at optimum MC for milling (12−14%)
  • Yellow – paddy is safe for seed storage (12% or below)

Within the range of 10−16%, the moisture content can be determined in 1% increments by observing the lighting patterns of the LEDs. For details see the photo below and the user manual.

The moisture tester is calibrated for paddy. Calibration functions for maize and other crops can be produced on request.