Obtaining Product Measurements
To measure the thickness of a product layer, lower the probe into the well until the signals activate. If there is an oil/product layer on the top of the water (LNAPL), the light and tone will be steady, indicating an air/product interface.
Read the depth off the permanently marked tape. Lower the probe further into the water, where the signals become intermittent, then pull back up and take a reading at the product/water interface. The thickness of the product layer is then determined by subtracting the first reading from the second.
If there is only water in the well and no product, there will only be intermittent (water) signals. The presence or absence of dense (sinking) non-aqueous layers (DNAPL) is determined by continuing to lower the probe to the bottom of the well.
If the steady tone and light return, this indicates a non-conductive liquid. Measure the depth and continue lowering the probe until it touches bottom and the tape goes slack.
To determine the thickness of the DNAPL layer, subtract the first reading from the bottom depth.
Each full size meter is provided with a grounding cable, cleaning brush, a convenient carrying case with shoulder strap, and a tape guide/datum.
The tape guide may be used to provide support for a small reel on the well casing. It acts as a datum allowing repeatably accurate measurements; ensures that the probe hangs in the centre of the well; and protects the tape from damage.
It is essential to use the grounding cable to ensure safety and proper function of the electronics in all applications.
The 122 Interface Meter uses the P8 Probe, which is 5/8" (16 mm) in diameter and stainless steel. It is pressure proof, up to 500 psi. The beam is emitted from within a Hydex cone-shaped tip. The tip is protected by an integral stainless steel shield, and is excellent for the vast majority of product monitoring situations.
Laser Marked PVDF Flat Tape
The PVDF flat tape is extremely accurate, traceable to NIST and EU measurement standards.
The easy-to-read markings on the 3/8" (10 mm) PVDF flat tape are permanently laser-marked. The dog bone shaped tape avoids adherence to wet surfaces in wells. It is resistant to most chemicals, and the smooth surface of the tape is easy to decontaminate and easy to handle.
LM2: Feet and tenths: with markings every 1/100 ft.
LM3: Meters and centimeters: with markings every mm.