Closed Cup Flash Tester. At first glance, one might think it to be a new high tech espresso machine.
The device is designed to determine the flash point of liquid products. Flash point refers to both flammable and combustible fluids. Classifying the flammability of fuels and other materials by their flash point value has been an established practice for more than 100 years. The fundamental reason for measuring flash point is to assess the safety hazard of a liquid with regard to its flammability. International and National Regulations make it mandatory for the testing of specific liquids to be performed. Classification are used to warn of a risk and to enable the correct precautions to be taken when manufacturing, storing, transporting or using the liquid.
The Koehler model (pictured on the left) uses the Tag Closed Cup Method, where the vapours above the liquid are not in temperature equilibrium with the liquid. Closed cup testers normally give lower values for the flash point than open cup (typically 5-10 °C) and are a better approximation to the temperature at which the vapour pressure reaches the lower flamable limit. Closed Cup Testers can use either an electric or gas method of heating. Features includes stepless variable heat control with a reference dial for accurate repeat settings of temperature rate and rise per required specifications. A cover mechanism simultaneously opens the slide shutter and the applies a test flame. This model includes:
- Liquid bath with constant level overflow
- Brass test cup (replacement test cups are available as a consumable)
- Plated brass thermometer ferrules
- Test flame reference bead
The Open Cup model (pictured on the right) works in a similar way for measuring the flash point of liquids and vapors. At certain intervals a flame is brought over the surface. The flash point will vary with the height of the flame and at sufficient height, the measured flash point temperature will coincide with the fire point. (the point at which a fuel will continue to burn for at least 5 seconds on its own, after being ignited).
Liquids that are common for being tested include:
- Diesel Fuel
- Jet Fuel
- Vegetable Oil