Independent comparisons. We may earn from shop links. More info

Grain moisture probe or cup meter

Updated: 22 October 2026

You are choosing between a rod you can push into a bin and a cup you fill on the tailboard. A grain moisture probe or cup meter is not one job with two handles. A probe can find a wet patch. It does not replace a sample when you sell wheat or dry to a contract. A cup measures grain you have removed. None of these seven amazon.co.uk listings includes a grinder. The seven cards are the [grain moisture meter comparison](/hub/measuring-equipment/grain-moisture-meter). Peter F. used the captures and AHDB’s meter guidance on 21 October 2026 and did not oven-test them. A qualifying Amazon purchase can earn a commission at no extra cost to you.

You are choosing between a rod you can push into a bin and a cup you fill on the tailboard. A grain moisture probe or cup meter is not one job with two handles. A probe can find a wet patch.

Our top picks

AMTAST AMTAST AMT65C

Best overall

AMTAST AMTAST AMT65C
7.2/10about £148.45
View offer
Oumefar Oumefar double-bar probe

Alternative

Oumefar Oumefar double-bar probe
3.9/10about £23.79
View offer
WapoRich WapoRich RQ-W65pro, 593 g

Best value

WapoRich WapoRich RQ-W65pro, 593 g
7.6/10about £192.69
View offer
On this page
  1. 1.A probe scans a bulk
  2. 2.A cup measures a sample you removed
  3. 3.What the seven listings actually are
  4. 4.Which to buy for which job

A probe scans a bulk

AHDB allows a probe for a rapid check of a bulk and refuses it as a stand-in for a sample meter. Spears put in less than about 0.5 m read low, and resistance probes need about a minute to settle. Sinar points a spear at the store and a conventional meter at buying and selling, because that is what the merchant uses. These rods do not state a length. In a 100-tonne floor store, stabs along the wall might read 13% and a stab over the fan duct 16%. Mark the spot, then test grain drawn from beside the duct.

A cup measures a sample you removed

Cup compression is a cell you fill and tighten until the listing’s signal says the lid is home. The two RQ-W65pro pages describe that beep, state ±0.5% and 0.1%, and store 250 readings. They do not state a sample volume. B0GGGH539C is £192.69 and 593 g. B0GGGTH5M5 is £208.00 and 432 g, and it names oilseed rape. Do not average the weights. The ±0.5% line stays a seller claim. Put the cup on the tailboard, not on your knee. AHDB’s notes record a capacitance meter about 0.4% out when it sat at about 30 degrees. A beep is not a grinder. A Unimeter starts from £305 excluding VAT. The probe only tells you where the next sample should come from.
AMTAST AMTAST AMT65C

Testsieger

AMTAST AMTAST AMT65C
7.2/10about £148.45
View offer

What the seven listings actually are

Three listings are rods, and none prints a length. Oumefar at £23.79 is a double-bar probe whose title also says moisture meter wood. The United Kingdom review of 30 September 2026 says two units were not fit for grain. YUKERMARB at £31.09 names hay and has no star line. Ayayu at £31.40 leads with hay, and the United Kingdom review of 5 October 2024 says there is no hay setting. HavenlyCove at £102.59 states resistance, names coffee and cocoa, and does not describe a cup, a grinder, or wheat. AMTAST lists wheat and barley. Overseas reviews mention tightening a lid. That is not enough to call the listing a cup. Who should buy which row is on the best grain moisture meter page.

Which to buy for which job

Choose a probe to walk a store for a wet patch you will confirm with grain you remove. Choose the £192.69 cup when you need wheat and barley named and you accept an empty star line. Choose the £208.00 page when you also need oilseed rape printed. Choose a grinder, from about £305 excluding VAT, when you will be held to the number. Sell on a sample, and walk the store with a probe. Temperature and the 0.5% margin are on how to measure grain moisture. If a hay stack is already hot, that is a fire-service matter. The purchase checklist is the grain moisture meter buying guide.

Common questions

When do you need a cup or a grinder?
You need a cup or a grinder when the grain has been removed and the number has to be compared with another test. A cup in this set is the WapoRich compression cell. A grinder is the missing class, from about £305 excluding VAT for a Unimeter at a UK farm shop. Use the grinder when you will be paid on the figure. Use a cup from these listings only if you are staying inside the set and you accept that there is no star line.
How deep does a probe need to go?
AHDB’s meter work found low readings when the probe was shallower than about 0.5 m. That is a depth from the guidance, not a length printed on Oumefar, YUKERMARB or Ayayu. Those pages do not state how long the rod is. If the steel cannot reach half a metre into the bulk, you are reading the outside. Mark the spot, then test grain you have taken out.
What is cup compression?
It is a sample cell you fill and close until the lid is tight. On both RQ-W65pro listings, an audible signal marks that point. The pages state 0.1% resolution and ±0.5% accuracy, store 250 readings, and show temperature. They do not state how much grain the cup holds. The ±0.5% figure is the seller’s claim. It has not been compared with an oven on UK wheat in this research. Set the cup on a level surface before you trust the screen.
Is a resistance meter the same as a grinder?
Not on these pages. A grinding resistance meter crushes a sample and then compresses it. HavenlyCove states resistance and automatic temperature compensation, and it does not describe a grinder or a cup. It also does not name wheat. Under-compressed grain and worn grinder plates read low on a true grinding meter, by about 1% for worn plates in AHDB’s notes. You cannot assume HavenlyCove performs that grind because the word resistance appears in the bullet.
Why do two RQ-W65pro listings disagree on weight?
They are two amazon.co.uk ASINs with the same model name. B0GGGH539C is £192.69 and 593 g. B0GGGTH5M5 is £208.00 and 432 g, with dimensions given as 16.5 cm wide by 7.4 cm high, and it names oilseed rape. The cheaper page does not name rape. The captures do not explain the 161 g gap. Report both figures. Do not average them into a single weight for the RQ-W65pro.

Related pages

Hay moisture meter

Grain moisture meter

Best grain moisture meter: sample, probe or grinder

Grain moisture meter buying guide: job, curve, check

How to measure grain moisture: sample, then repeat

Wheat barley storage moisture: below 14.5% and 18%

Sources

Public UK sources from the research digest. Shelf prices and star lines are the amazon.co.uk figures for these seven listings. The price band is this set, not a market average. A seller’s ±0.5% line is not an oven result.

  1. AHDB: how to use a grain moisture meter (retrieved 22 October 2026)
  2. AHDB: grain storage moisture targets (retrieved 22 October 2026)
  3. AHDB: pests, fungi and ochratoxin A (retrieved 22 October 2026)
  4. AHDB: hazards in longer-term grain storage (retrieved 22 October 2026)
  5. FSA: mycotoxins publications (retrieved 22 October 2026)
  6. AIC Grain storage guide 2023 (retrieved 22 October 2026)
  7. ISO 712-1:2024 cereal oven method (retrieved 22 October 2026)
  8. Devon and Somerset Fire and Rescue Service: storing hay safely (retrieved 22 October 2026)