Tool of the month: Pinless Moisture Meter

Name: Pinless Moisture Meter 

Cost: $85 to $100

Available at Home-Depot, Amazon, and manufacturers’ websites

Intended use

A Pinless Moisture Meter device can measure litter moisture at the poultry barns. The litter moisture should be maintained between 20% and 25% during the flock. Drinker management, bird health, bird density, ventilation rates, litter depth, and litter type can affect the litter moisture.

How does it work?

The device is a non-invasive instrument that can detect moisture up to ¾ inch (19 mm) below the surface of the litter. It infers the level of moisture from the material’s capacitance, which the meter measures by gauging its effect on an electric field that the meter generates each time it is powered on. The device exploits two physical phenomena to make its measurements. 

  1. The linear relationship between a solid material’s moisture level and its dielectric constant, and therefore its capacitance.
  2. The so-called fringing-field effect-the slight spreading of the electric field produced by current flowing between two electrodes when both electrodes are on the same side of a material.

Behind the back cover of the device are two metal plates. When the device is powered on, the plates are given small and opposite charges. The potential difference causes current to flow, creating a three-dimensional electric field. When the back of the device is placed against the litter materials, the increased capacitance of the material distorts the electric field to an extent that can be sensed and measured. Displaced readings reflect the average moisture level of the litter between its surface and the electric field’s maximum penetration of ¾ inches. Moisture closer to the surface has a greater effect on readings than moisture at the maximum penetration depth.

Using the device

To use the device in a poultry barn, follow the following steps:

  1. Mix the litter materials thoroughly at the measurement place to have a consistent and compact sample with minimum porosity.
  2. Press and hold the power button for at least three seconds.
  3. Press the right/left arrow buttons to choose the material type. For the litter, the softwood option probably would be a reasonable choice.
  4. Scan the litter material by gently pressing the inductive sensing area on the back of the device against the material.
  5. The LCD will read out the material’s moisture content in %WME (Wood Moisture Equivalent).
  6. To hold a reading, press the “Hold” button briefly. The display will show the held value, along with a lock icon above the % sign. 

An important tip about measuring litter moisture

The porosity of litter materials might cause inaccurate readings. Litter materials should be mixed to avoid the porosity’s effect as much as possible. To test the accuracy of the protocol and measurements, producers might consider using the oven method to measure the litter moisture. In this case, they will need to take litter samples from different areas at the barn, mix the samples thoroughly, and seal the sample in a bag before sending them to a lab. In the lab, 50 to 100 g of the litter sample will be placed in a pan and dried in a 120°F oven for 24 hours. Then the moisture percentage will be calculated by dividing the dry weight of the material by the wet weight and multiplying the result by 100.

About the author(s)

Research Associate at Poultry Innovation Partnership | + posts