Vasthi (Model VS-70 E) HAND HELD PORTABLE COMBUSTIBLE GAS DETECTOR is a compact battery operated portable instrument used for taking an air sample and indicating the presence and concentration of combustible gas. Samples of the air under test are drawn by means or a rubber aspirator bulb and analysed for combustible gas content on a heated platinum filament in a Wheatstone bridge measuring circuit. A built-in meter indicates combustible gas content in units of explosibility. Power for operation or the instrument is provided by Lithium ion battery. A probe and extension hose permit withdrawal of samples from remote locations and the instrument fits in a compact leather case with over the shoulder carrying strap. The model VS-70 E is suitable and recommended for testing tanks, manholes, vessels, pressure cylinders, pipelines, and other closed systems or confined spaces to determine presence or absence of combustible gas. It is a valuable aid for safety of operations whenever combustible gases or vapors are handled.