FP-21C Flush Mounted On-Line Moisture Sensor

Reg. U.S. Pat. Off. No. 6,249,130 B1


  • Accurately monitors moisture content in grains and other particulate materials
  • Designed for physically hostile environments such as mixers, chutes, conveyors, and augers
  • Reliable, rugged, economical solution for moisture monitoring applications
  • Easily integrated into process control systems

Product Specifications

FP Series sensors feature proven capacitive moisture sensing technology in a flat plate configuration. This allows its mounting in a mixer, an auger, a chute, or a sled riding on granular material being transported by a belt conveyor for continuous measurement of moisture content.

Its analog moisture and temperature outputs can be displayed on our Moisture Display System (MDS) and/or transmitted for integration into a process control system.

Measurement accuracy
Particulate sample temperature ±1°F
Particulate moisture content (typical) ±0.25%
Moisture 0 to 5VDC
Temperature 0 to 2VDC
Minimum sample depth 4 inches (10 cm)
Operational Temperatures
Sensor, ambient -40°F to 155°F
Particulate sample 0°F to 100°F (Others optional)
Electrical power
Required 10VDC to 12VDC
Consumption 2 Watts maximum
Physical size
Surface dimensions (inches) 4.625 X 7.625
Materials of construction
Sensor face Ceramic
Sensor body Electroless nickel-plated aluminum
Sensor body 316 Stainless Steel
MDS operator interface Can serve one or two sensors
Defined Area Flow Restrictor (DAFR) For chute mounting
Sled mount For belt conveyor mounting
Hinged door mount (shown) For mixer or auger mounting