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Solinst Interface Meters

Solinst LogoSolinst interface meters provide accurate and easy-to-read measurements of both light and dense non-aqueous phase liquids (LNAPL and DNAPL) in wells and tanks. Designed for use by environmental professionals in the field, Solinst interface meters are stable and reliable when deployed correctly. Their high-quality design includes a factory-sealed probe that detects liquids and conductivity using infrared refraction. Certified as intrinsically safe, Solinst Interface Meters have a grounding strap that allows for use in explosive environments and other hazardous locations.

Environmental Equipment & Supply offers both iterations of Solinst's interface meter:


122 Interface Meter
The Completely New 122 is Solinst's standard-sized interface meter, now available with a laser marked PVDF tape. The meter features the standard 5/8"-diameter P8 probe.



Most Popular
122 Interface Meter

New Laser Marked 122M Mini Interface Meter
The New Laser marked 122M Mini interface meter comes with tough PVDF cable that is easy to clean.

122M Mini Interface Meter


Features and Benefits

Both the 122 and 122M share the following features durability and for ease of use:

  • Factory-sealed, pressure-proof probes featuring optical and electronic sensors.
  • Sensors are aligned and calibrated to the same zero point and require no end-user maintenance other than occasional cleaning.
  • Sensors are accurate to 1/200th ft. or 1 mm.
  • Non-stretch, corrosion-proof tape that resists kinking and is easy to splice if necessary.
  • The unit is powered by a pair of standard 9V batteries which provide a minimum 120 hours of operation.
  • Automatic shutoff after 10 minutes helps preserve battery life.
  • 3 year warranty.

Operating Principles

Solinst interface meters produce two distinct warnings when deployed into a well or tank:

  • A steady light and tone indicates the presence of a non-conductive liquid.
  • An intermittent light and tone indicates the presence of water only.

To use a Solinst interface meter, deploy the probe into the well or tank. When the sensor first comes in contact with water, a steady light and tone will indicate a layer of floating (LNAPL) product on the surface. The probe can then be slowly submerged to the bottom to test for sinking (DNAPL) product mixed in with the water itself.

To determine the thickness of a LNAPL or DNAPL layer, simply subtract the reading taken when the steady tone began from the reading taken when it reverted to an intermittent (water-only) tone.

Get Solinst Interface Meters From Environmental Equipment & Supply

For ordering and pricing information about Solinst interface meters, contact Environmental Equipment & Supply today. We are an authorized nationwide Solinst dealer that has been providing precision equipment to environmental professionals for over 25 years. Our team is available anytime between 7am and 6pm, Monday to Friday, to answer all your questions.