Virtual Valve Museum
Virtual Valve Museum | search: (use * for wildcard)
About the museumMuseum exhibitsUpdates, new exhibits etc.EquipmentSupporters
*DocumentsValves wanted!Valves for sale or for tradeLinks to other sites, suppliers etc.

Ozotron (EEV)

An ozotron is a device which will detect minute quantities of halogen or halogen compound gasses in the atmosphere. It consists of two concentric cylindrical electrodes, the inner cylinder being heated to approximately 800C by an internal heater.

The air to be tested is drawn through the annular space between the electrodes and a voltage applied across the gap. The heated inner cylinder is the anode.

The electrodes are enclosed in a protective envelope. Type H (see example) has a glass envelope and type J (see example) is ceramic. The ceramic type can be dismantled for cleaning.

Under clean air conditions and with an anode voltage of 240V d.c. a very small ion current flows in the anode circuit. However if air containing halogen vapour such as freon or trichlorethylene is introduced into the ozotron the positive ion current is increased. The increase in anode current provides a measure of the halogen vapour concentration in the air being sampled, and can be amplified to operate either an alarm or a meter.

The principal application of the ozotron is in leak detection equipment. The vessel or system to be tested is filled with a halogen vapour slightly above atmospheric pressure and any leaks may be traced by monitoring the ozotron current while sampling air from the suspect areas.

The ozotron is capable of detecting halogen concentrations of 1 part in 1,500,000. A leakage of Arctron (dichlorodifluoromethane) at the rate of 1.5 milligrams per day (0.02 ounces per year) can be located.

This file was last modified 15:13:35, Tuesday September 02, 2014