Sensit Company

Wind blown erosion measurement solutions


New Model H14-LIN shipping today
The standard erosion sensor Model H11-LIN has been upgraded and is replaced by the new Model H14-LIN. The new model has stainless steel flexible cable shielding. It also does not require a radial symmetry calibration due to the exceptionally consistent and uniform radial response. This new sensor is now in production and is currently shipping. Restoration of the Sensit machine shop is complete Sensit is back to normal operation. Sorry for the 6 month interruption we both have had to endure.

Sensit company (started in 1978), is the leader in erosion measurement sensors. Design of these sensors has been provided in part by the USDA-SBIR (Small Business through Innovative Research) program. We have been awarded three SBIR research grants for erosion sensor design and feasibility. All three research studies were successful.


Sensit company currently manufacturers two state-of-the-art, remote site erosion sensors as shown below. The model H11-LIN is vertically mounted above the surface of the ground and is used for mass flux and movement monitoring. The model FP5 is an extremely sensitive flat plate surface movement detector providing data the instant movement occurs. When this data is processed with wind speed data, very accurate values for threshold of movement (wind speed or stress, U*) throughout an erosion event is easily determined.

H11-LIN Eroding mass flux sensor

Model H11-LIN Wind Eroding Mass Flux sensor. A cylindrical crystal is suspended between rubber mounts on a 2.54cm diameter stainless steel post. The crystal surface is hardened stainless steel. Data outputs for the number of particle impacts and movement via kinetic energy are TTL/CMOS pulses to be counted by any data logger capable of high speed counting. Power required is 0.84 watts (12V@70ma).

FP5-RevC Surface movement sensor

NEW! Model FP5 Flat Plate Movement Sensor. The sensor's active surface is 2.54cm in diameter and extremely sensitive. Like the H11-LIN, produces a TTL/CMOS compatible pulse for each particle impact. The low power requirement is 103mW at 12V supply voltage. The acceptable voltage range is 7VDC -> 20DC. The current draw for the entire voltage range is a constant 8.6ma.  Like the H11-LIN the FP5 is well suited for remote use under all environmental conditions including the extreme environment of Antarctica. It comes with 6 meters of shielded cable (stainless steel wrapped conduit, 7mm OD). There are three wires; +12V (red), ground (black) and a particle count output wire (green). The sensor comes with 600u and 1,000u glass spheres for quick testing. A 9V battery and a prewired connector for the battery is supplied so it's response can be tested on your desk when it arrives. A detachable wind diffuser is also supplied to help prevent scouring around the sensor in sand. This disk is 2mm thick plastic and will be replaced free except for a UPS letter pouch shipping cost. The sensor base has a 1/4"-20TPI hole in the bottom for mounting. This will fit most camera tripods. A variety of stainless steel hardware is also supplied for attachment including a 1/4" x 9" shaft that screws into the base to penetrate the ground keeping the sensor upright and misc. bolts, threaded stock etc. are also included.

Model FP5-RevC Surface Movement Detector


This new sensor became available in January, 2013. It is provided as a complete package with mounting hardware, glass spheres, battery and 4GB USB stick with technical documents for both erosion sensors. The orange disk is a wind diffuser that thwarts scouring around the sensor base by allowing sand to fill in gaps about the sensor. The goal is to allow surface movement called "creep" to move along the ground in a natural way to the sensor.

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USDA funded research for the H11-LIN

Sensit Company has been awarded 4 USDA-SBIR (Small Business through Innovative Research) research grants; three were for erosion sensor studies. The model H11-LIN sensor was awarded Phase I feasibility study and Phase II commercialization research grants. USDA/SBIR funding provided the opportunity to thoroughly understand the true response of the sensor and establish many essential design criteria like the necessary dynamic range of the response to adequately process the energy of very small impacts to extremely large impacts traveling over a wide range of velocities including particle mass also over a wide range. The required dynamic range for sensor response was found to be ~105, a difficult task. Sales slowly but continually increased since 1981 until the sensor, casually became referred to as simply the "Sensit" and eventually became an industry standard term.

Sensit Company was also awarded a USDA-SBIR Phase I feasibility study for the flat plate sensor. This effort was very successful in designing an impact sensor with a dynamic range of 106. New, state-of-the-art  technology is used throughout the design allowing an excellent application specific design that operates at low power. 

Sensit Company was also awarded a USDA-SBIR Phase I feasibility study toward the understanding of a design for a soil moisture sensor. The study found the sensor to be feasible but the industry of primary market interest turned their attention to real-time satellite weather data to determine irrigation requirements in advance. There is no viable market for a soil moisture sensor at this time.

In 1993 - 1995 Sensit Company produced a full 4pi sphere multi-channel scanning radiometers called the PARABOLA III (Portable Apparatus for Rapid Acquisition of Bidirectional Landmass Areas) shown below. Long ago the first PARABOLA, produced by NASA was a three channel scanning radiometer with 12 bit resolution. The Sensit PARABOLA III (complete re-design) upgraded this to 8 channels (near infrared, PAR and visible bandwidths), each having 20 bit resolution of reflectance data. Two of these systems were produced by Sensit and purchased by NASA and JPL for ground truth reflectance calibration of the MISER satellite off-NADIR data. Off-NADIR refers to satellites capable of "looking" in directions other than straight down.