Geneq > Materials Testing > Percometer
Percometer
model H-4112

H-4112 shown with surface probe. Other probes available,
see other side.

The Percometer is a reliable, accurate, lightweight and easy-to-use instrument for measuring the dielectric value (er), electrical conductivity (J) an temperature of materials indoors and outdoors. Dielectric value is an indication of the volumetric moisture content and the state of molecular bonding in a material. Electrical conductivity is a reflection of ionic concentration, water content and temperature.

Moisture Damage (Structural damage)
When moisture infiltrates a wall, causing damage, er values will be significantly higher than those from undamaged areas of the wall.

Tube Suction Test (Aggregate moisture susceptibility)
Measuring the suction properties of bound and unbound aggregates and road materials. This passive capillary test demonstrates a materials’ capacity to adsorb water if available, free water content directly affects mechanical performance of an aggregate.

Asphalt Air Voids (Pavement quality control)
Air is also one of the volumetric components that influences er. Measuring er can provide an indication if a pavement has been sufficiently compacted.

Soil Moisture
Since er is a function of the amount of free water in a material, Percometer can be an effective tool for determining soil moisture.

Frozen/Unfrozen (Soils and Road Structures)
When the free water in a material freezes the conductivity drops to around zero and er values decrease to values ranging from 4 to 12.

Frost Susceptibility (Soils and subgrade)
A strong correlation exists between er and frost susceptibility of unsaturated soils.
Salinity/Sulfates
 J is a function of soil salinity, colloid content and temperature. The presence and fraction of sulfates is an important factor in determining if road subgrade can be stabilized with lime

Fertility
 Forest regeneration species selection Regeneration potential of a soil can be assessed using er value.

Snow (Ski wax control)
The amount of unfrozen water determines the friction properties of snow (slipperiness). er values provide an indication of this amount and can be used to determine how much fluor should be applied to skis.

Temperature Useful for evaluating whether changes in electrical conductivity are due to temperature or changes in ionic concentration.

The Percometer utilizes two basic probe types, of which there are some variations. The surface probe has been designed for measuring tile walls, aggregate samples and liquids. While the probe utilizes non-destructive technology, its measurements have an effective penetration depth of 2 - 3 cm, depending on the medium. The tube probe has been designed for insertion into soft materials (minimum depth 10cm required for accurate measurements) and is ideal for measuring forest soils and road subgrade. Percometer permits the use of multiple probes with the same central unit. Each probe is identified by the central unit by its unique probe number, and uses a probe-specific calibration table in the central unit’s memory.

PROBES

Surface Probe SF (60mm dia.)
 er (1 to 40) with an accuracy of +/- (0.1 + 1%)
Electrical conductivity (0 to 9999mS/cm)
Temperature (-40 to +80C)
Recommended applications: Laboratory use, Tube Suction
Test, detection of moisture in structures with even surfaces
(e.g. behind shower room tiling)

Surface Probe SV (60mm dia.)
 er (1 to 200) with an accuracy of +/- (0.25 + 2%)
Electrical conductivity (0 to 9999mS/cm)
Temperature ( -40 to +80C)
Recommended applications: Laboratory use (high Er)

Short Tube Probe TFS (L = 18 cm)
 er (range: 1 to 15) with an accuracy of +/- (0.05 + 1%)
Electrical conductivity (0 to 9999mS/cm)
Temperature (-40 to +80C)
Recommended applications: Laboratory tests, e.g. triaxal
testing of aggregates

Short Tube Probe TVS (L = 18 cm)
 er (range: 1 to 90) with an accuracy of +/- (0.25 + 2%)
Electrical conductivity (range: 0 to 9999mS/cm)
Temperature (range: -40 to +80C)
Recommended applications: Percostation; laboratory tests

Long Tube Probe TVL (L = 100 cm)
 er (range: 1 to 90) with an accuracy of +/- (0.25 + 2%)
Electrical conductivity (range. 0 to 9999mS/cm)
Temperature (range: -40 to +80C)
Recommended applications: Field measurements (high er)

Long Tube Probe TFL (L = 100 cm)
 er (range: 1 to 15) with an accuracy of +/- (0.05 + 1%)
Electrical conductivity (range: 0 to 9999mS/cm)
Temperature (range: -40 to +80C)
Recommended applications: Field measurements

Surface Probe SF1 (diam = 60 mm)
 er (range: 1 to 200) with an accuracy of +/- (0.1 + 1%)
Temperature (range: -40 to +80C)
Recommended applications: Laboratory use

Operating Modes

The Percometer can be operated in two different modes:
Local Operating Mode: the standard mode of operation
when using the Percometer as a hand-held stand-alone
measuring instrument. All relevant information is
displayed on the unit’s LCD and the device itself is
operated using an integrated keyboard.
Remote Operating Mode: the Percometer is operated,
via modem or serial connection, using special software
supplied with the unit. All relevant values are shown on
the PC display and the central unit’s integrated keyboard
is inactive.
Dielectric value (er) measurements
 • Measurement range varies according to probe type
• Measurement frequency: 40 - 50 MHz
• Measurement method: er is measured through the change in the electrical capacity of the electrode (probe)
attributable to the influence of the material being
measured. The term dielectric constant er is used here to
indicate the real part of the complex relative dielectric
permittivity (er).
• er measurements are reliable when the conductivity of the material being measured is:
< 1000 μS/cm for Tube Probe measurements
< 2000 μS/cm for Surface Probe measurements
Conductivity (J) Measurements
 • Measurement range: 0 to 9999 μS/cm
• Measurement frequency: 2 kHz square wave signal
Data storage, PC connection
 • Number of measurements stored: 1000
• 24 calibrated probes can be attached to a Percometer:
• Data transfer to PC via RS232; modem optional
Power supply and battery management
 The Percometer is powered by an internal 12 V, 1.5 Ah battery, which ensures a minimum of 8 hours continuous operating time. It can also operate using a +9 to +14 V external power supply.