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Gazeeka Model 851 Moisture Gauge


$16,370.00 ex. GST

The Model 851HP moisture sensing platform for hay processing plants, available with universal adjustable stands and ability to connect to any PLC via current loop or Modbus TCP.

  • Autonomously collect valuable moisture data
  • Instantaneous, Maximum (Peak) and Average moisture, bale-by-bale.

Extremely accurate, reliable and trusted in the industry for many years.

Gazeeka Model 851 Moisture Gauge

The Vomax Model 851 instrument uses microwave techniques to measure the moisture content of a pressed bale.

Vomax instruments use techniques that are based on sound scientific principles, which have been proven in the laboratory and verified in the field. The instrument measures the speed of the microwaves and the amount of microwave energy absorbed through the bale.

The speed of microwaves through air is very close to the speed of light through space, and the speed of microwaves through dry fibrous material is a little slower than through air. However, the speed of microwaves in water is considerably slower than that in dry fibrous material. The difference in this speed is attributed to a value known as the dielectric constant (or sometimes called relative permittivity). The dielectric constant for air is close to 1, for dry fibrous material it is closer to 2 while for pure water it is approximately 80. Similarly, the amount of microwave energy absorbed in air is less than dry fibrous material and in dry fibrous material is much less than in water. Thus, if measured correctly, these measurements can be a very sensitive method of measuring moisture in the bale.

Other factors, such as the density of the bale, temperature of the material being measured and even the way the bale is packed (pressed) also need to be taken into account. All of these factors, and more, have been taken into account in the Vomax moisture monitor measurement system to give you an accurate and reliable real time, on-line moisture measurement system.

Reliable, proven technology.

  • Many units have now been operating reliably for more than 10 years.
  • Hundreds in use on hay balers.
  • Non contact measuring technique.
  • Easily installed.
  • Two simple industrial interfaces to connect into the plant PLC.
  • Bale by bale moisture value and average moisture.


Parameter units Value


  • Moisture range % as received 3 to 12
  • Repeatability % moisture as received * 0.2
  • Precision % moisture as received * 0.7
  • Material temperature degrees Celsius 10 to 45 (50-1100F)
  • Bale density Kg from nominal weight +/- 20 KG (+/- 45 lbs.)
  • Bale Moisture distribution % moisture WB less than 0.5%

* at one standard deviation for one size bale


Current Loop milliamps 4 to 20
Current loop isolation Volts 350
Current loop drive ohms 80 to 600 (with 24V supply)
80 to 150 (with 12V supply)


Protection IP IP55 (NEMA 4)
Humidity % relative humidity 0 to 100 non condensing
Vibration G’s 10 to 100 Hz, 0.5mm 0 to 2.5
Shock G’s 3 times in 3 directions 5
Temperature degrees Celsius 0 to 40 (32-1050F)


Voltage: (+/- 10%) 24V DC
Power: Watts 50
Physical Connection internal cable connections
Distortion % total harmonics 5
% any single harmonic 3

Package Contents

    • 851HP Active Antenna
    • 851HP Passive Antenna
    • 851-E17-10M-R01
    • 851-E24-4M-R00
    • Terminal Box
    • PSP12-DC24-2
    • 851HP Owner’s Manual
    • 851-M11-R00
    • 851-M06-R00
    • 851-M18-R00

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