Solinst Model 122M Mini Interface Meter

Solinst Mini Oil/Water Interface Meters give clear and accurate measurements of product level and thickness in wells and tanks. Determination of both light (floating) non-aqueous phase liquids (LNAPL) and dense (sinking) non-aqueous phase liquids (DNAPL) is quick and easy.
The Model 122M Mini Interface Meter with laser marked cable is a convenient small version, which can easily fit in a backpack or an optional custom mini carry case. It uses narrow laser marked cable in 25 m or 80 ft lengths.
The Mini Interface Meter enhanced electronics include automatic circuitry testing; 300 hours of on-time battery life; clear signals; and high accuracy. The circuits are powered by one standard 9V battery housed in easy-access drawer in the faceplate.

Operating Principles
Product (Non-conductive liquid) = Steady light and tone
Water (Conductive liquid) = Intermittent light and tone
To detect liquids, the Model 122M Mini Interface Meters use an infra-red beam and detector. When the probe enters a liquid the beam is refracted away from the detector which activates an audible tone and light. If the liquid is a non-conductive oil/product the signals are steady. If the liquid is conductive water), the conductivity of the water completes a conductivity circuit. This overrides the infra-red circuit, and the tone and light are intermittent.
Both sensors use exactly the same zero point, giving accuracy as good as 1.0 mm or 1/200 ft. The high accuracy enables the sensors to detect the slightest sheen of oil on the surface of the water.
Hazardous Locations Use
The Model 122M Mini Interface Meter with cable has been approved by QPS for use in hazardous locations, Class I, Div 1, Groups C&D based on CSA Standards. It is also ATEX certified under directive 94/9/EC, as II 3 G Ex ic IIB T4 Gc.
The ground cable is a safety essential when the meter is used in potentially explosive environments. It also ensures that the electronics are properly protected.