DeAerators • Semiconductor Piezometers • Thermistors • Temperature Gages • Cables

Photo of Model 2100



Model 2100 Nold DeAerator™
De-aired water or antifreeze solutions are an essential ingredient of any hydraulic piezometer or settlement system, where the formation of air bubbles in the fluid filled tubing must be prevented. The Nold DeAerator provides a rapid means of removing dissolved gases from fluids, at a much higher rate than through conventional heating/boiling methods. The Nold DeAerator consists of a holding tank, which can be evacuated using either a vacuum pump or a water-powered aspirator. Water, (or antifreeze solution), is drawn into the tank where it is agitated violently by a rotating impeller, causing cavitation, nucleation and the rapid expulsion of the dissolved gasses. The Nold DeAerator can also be used with other fluids to remove dissolved gasses.

Standard Capacity 6, 8 liter
Power Supply 120 V 60 Hz or 240 V 50 Hz
Power Consumption 14 watts
Vacuum Requirements 750 mm Hg, (12 Torr), or better
Degassing Purity 0.6 ppm
L x W x H (6 liter) 190 × 190 × 510 mm
(8 liter) 190 × 190 × 600 mm

Photo of Model 3400  

Model 3400, 3410 Semiconductor Piezometers and
Pressure Transducers

The Model 3400 Semiconductor Piezometers and Pressure Transducers are intended for dynamic measurements of fluid and/or pore water pressures in standpipes, boreholes, embankments, pipelines, pressure vessels, reservoirs, etc. They are also used for static pressure movement where the readout system is incompatible with vibrating wire type transducers. Three transducer output options are available.

Standard Ranges 0.1, 0.15, 0.25, 0.4, 0.6, 1.0, 1.6,
2.5, 4.0 MPa
Over-Range 2 × rated pressure
Output 10 mV/v, 4-20 mA, 0-5 V
Accuracy ±0.25% F.S. or better
Linearity < 0.5% F.S.
Temperature Range –20°C to +80°C
Length × Diameter 194 × 32 mm

Photo of Model 3800's  

Model 3800 Thermistor Probe
The Model 3800 Thermistor Probe consists of an interchangeable thermistor bead mounted inside a rugged PVC (Model 3800-1) or stainless steel (Model 3800-2) housing. They are used for remote readings, such as measuring hydration and cooling temperatures in placement of mass concrete.

Standard Range –50°C to +150°C
Sensitivity 0.1°C
Accuracy¹ ±0.5°C
Temperature Range –20°C to +80°C
Length × Diameter 50 × 12 mm
¹Accuracy of ±0.2°C available on request.

Photo of Model 3810  

Model 3810 Thermistor String
The Model 3810 Thermistor String comprises a number of individual 3800 sensors mounted in rugged, multi-conductor cables for multiple temperature measurements in a single borehole. Thermistor strings are manufactured according to customer requirements for overall length, number of sensors and accuracy.

Standard Range –50°C to +150°C
Sensitivity 0.1°C
Accuracy¹ ±0.5°C
Temperature Range –20°C to +80°C
¹Accuracy of ±0.2°C available on request.

Photo of Model 4700  

Model 4700 VW Temperature Gage
The Model 4700 VW Temperature Gage consists of a stainless steel transducer body to which a vibrating wire element is attached. As the thermal coefficients of expansion of the body and wire are different, a simple, yet sensitive, temperature measuring device can be constructed. These gages are ideally suited for use in projects that require data-logging and where other types of VW transducers are in use.

Standard Range 100°C (–20°C to +80°C)
Optional Range 200°C (–200°C to 0°C or 0°C to +200°C)
Sensitivity 0.034°C
Accuracy ±0.5% F.S.
Length × Diameter 127 × 19 mm

Photo of cables  

Geokon cables are designed for a variety of geotechnical and hydrological applications. They are waterproof, have good electrical properties and can be buried in soil or embedded in concrete. Cable construction consists of one or more shielded pairs with individual drain wires for electrical noise protection. A variety of cable jackets are available including PVC for standard applications, Teflon for use at high temperatures and Polyurethane for use in situations where extra abrasion resistance is required. Armored cables, for use in earth dams, and cables with straining wires and integral vent tubes are also available.

Conductors 22 AWG
(stranded 7 × 30 AWG) tinned copper
Conductor Insulation Polypropylene, 10-Mil high density,
color coded

Aluminum polyester with drain wire,
24 AWG tinned copper

Jackets¹ Extruded PVC standard (–20°C to +80°C),
Teflon (–80°C to +200°C), Polyethylene,
Polyurethane, and Armored Polyethylene
Temperature Range –20°C to +80°C
¹Other cable jackets are available for special applications.