Model 122 Oil Water Interface Meters

solinst model 122 oil water interface meters

The Model 122 Oil/Water Interface Meter is designed to measure floating or sinking hydrocarbon layers in water (LNAPL and DNAPL).

The Model 122 P8 5/8" (16 mm) narrow pressure-proof probe clearly detects when it enters product or water, with an accuracy of 1/200 ft. or 1 millimeter. It is excellent in almost all product monitoring applications.

It uses optical refraction and electrical conductance to determine product and water interfaces. A continuous light and tone indicate non-conductive product. Water is indicated by intermittent signals.

The depths of detected water and product layers are read off PVDF flat tape, which is laser-marked every 1/100 ft. or each millimeter. The durable, corrosion-resistant tape is easy to clean and ideal to use when measuring in wells, tanks, at refineries, landfills or remediation sites.

The Model 122 Interface Meters are certified intrinsically safe for use in explosive environments, and are ATEX certified.

One 9V battery provides a minimum 120 hours of life. The electronics have automatic circuitry testing and they shut off after 10 minutes.

solinst model 122 oil water interface meter p8 probe


Length Options:

Small Reel 100 ft. 30 m
  200 ft. 60 m
  300 ft. 100 m
Medium Reel 500 ft. 150 m
  750 ft. 250 m
  1000 ft. 300 m


solinst pvdf laser marked flat tape

LM2: Feet and tenths: with markings every 1/100 ft.
LM3: Meters and centimeters: with markings every mm


Laser Marked PVDF Replacement Tapes

Solinst measurement devices that use laser-marked PVDF flat tape, also use the same tape seal plug/probe connection. Therefore, replacement tapes are interchangeable and can be used with the 101 P7 Water Level Meter, 122 P8 Interface Meter, or 107 TLC Meter.

solinst laser marked pvdf replacement tapes



solinst oil water interface meter in well


solinst model 122m mini oil water interface meter


A Model 122M Mini Interface Meter has a small reel, designed for portability. It uses narrow 0.12" (3 mm) coaxial cable with a durable laser-marked PVDF jacket, in lengths of 80 ft. or 25 m.

The compact reel to fit easily in a backpack. The Model 122 Mini electronics provide up to 300 hours of use with one 9V battery. It uses the same P8 Probe as the Model 122.


solinst pvdf laser marked cable

LN2: Feet and tenths: with markings every 1/100 ft.
LN3: Meters and centimeters: with markings every mm


Once an oil layer is detected, a sample can be taken using the Solinst Model 425 Discrete Interval Sampler. The 425 Discrete Interval Sampler is excellent for obtaining no purge water samples from below and above product layers, and from within the actual product.