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How Do Maize Moisture Meters Work?

2 points by DavidWanjiru ↗ HN
I ask coz I want to make a mobile app that maize farmers in East Africa (I'm Kenyan) can use to check for moisture content in their maize, but phones don't come with built in moisture meters the same way they have gyroscopes, accelerometers and so on. I'm thinking of getting the basic electronic component for moisture measurement and moving it's data to a phone via USB where the app does the rest. So like a probe with the meter on one end that you plug into your sample of maize, a USB cable and a phone. I know google is my friend, but if you're already conversant with this, it'd help a great deal.

5 comments

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helen842000
You'd probably need to do some research with farmers. See what type of moisture meters maize and types of phones they have access to. Your app needs to work with whatever is currently in use.

Some use a probe, some are like a jug that contain the grain sample.

As far as I am aware the more modern devices can store to internal memory or SD card and export data via CSV file.

A lot of meters come bundled with software that can help farmers analyse the readings already so you may need to see what software is already in use too.

Ideally you could just use a wifi SD card in the meter and then use the phone to browse straight to the readings on the card which can then be imported into the app. No need for people to connect their phone via USB. This requires a smartphone though.

DavidWanjiru
I meant what is it do they actually measure? Turns out it's capacitance of the sample, with some compensation for temperature being made, so presumably they also have a thermometric function in-built. The devices my potential clients currently use cost about US$ 1,000, and are only typically found at grain collection centres (we're dealing with small-scale farmers). So I guess the challenge is not so much to build a smartphone app, or to even get the moisture readings into a phone, but to build a cheap moisture measuring device.
eng101
David, could you please ping me at ernest.g.n (google's mail service)
helen842000
The cheapest I've seen is around $40 if you were buying in bulk they'd be even cheaper. Maybe the easiest thing to test would be to import devices at a reasonable price and see if you can sell them.