3M-Polar Compound Tester/PCT 120

PCT 120 allows users to evaluate % polar materials in degrading oils.
According to the manufacturer, calibration of the unit allows accurate determination of polar compounds in the samples.
The user places a treated strip in the metallic well of the instrument and pours oil through a funnel so it contacts the strip. The operator pushes the ‘Start’ button and reads the result when a flashing green light indicates that the sample is ready. Results are read using an embossed scale on the lid.

3Μ-Range Shortening Monitor  

The Shortening Monitor test consists of a white paper strip measuring 1.0X10 cm which has four blue bands across it. They are used as a dip test to measure accumulated free fatty acids, similar to commonly used pH papers. The tests were developed to provide users, especially those in the fast-food industry with an inexpensive means objectively to measure cooking oil quality.
To conduct a test, the operator grips the strip at the top and immerses it in the hot oil for 1–2 seconds. All four bands must be covered. The strip is removed and excess oil is allowed to drain into the fryer. After 15 seconds the strip is held up to the light and the number of bands which have changed to yellow are counted.
The approximate free fatty acid (FFA) values for the bands are >2.0, > 3.5, >5.5 and >7.0%.

Merck-Fritest

Fritest is a colorimetric test that uses a solvent-based reagent system. The test reagent is placed into a sample tube to the fill line and hot oil is added to a second line. The tube is stoppered, gently shaken and read against the color scale after one minute. The color for each test is used to judge the quality of the oil.
The Fritest has a four-color scale and recommended that the oil be changed at color three and that it has ‘gone off’ at color four

EBRO-FOM 320

FOM 320 is used for the rapid measurement of  the content of total polar compounds in used oil.
Within the operation temperature of 160 - 200°C, the sensor of FOM 320 is submerged into the oil sample and the oil was stirred gently for 20 s to allow even distribution. FOM 320 typically showed a stable reading of the content of total polar compounds (%) within 1 min.
This rapid method detects the dielectric constant of oil. This constant is converted to the content of total polar compounds (%) based on the formula set up by the manufacturer.

Viscofrit

Viscofrit based on physical changes in the frying oil, which can be used as quick methods to evaluate indirectly whether the polar compound content has surpassed the 25% mark. Viscofrit measurements are based on changes in the viscosity of the oil
The test consists of measuring the time required in seconds for a sample of frying oil (totally liquid) to flow out of a cone-shaped funnel. The test can be applied in a temperature range of from 15oC to 50 oC, but temperatures between 20 and 30 oC are
recommended