Sierra Monitor Corporation T10008 - Manual (Page 3)

OXYGEN DEFICIENCY MONITOR PAGE 1
1. Introduction
1.1 The SMC Model 55 is a portable oxygen efficiency monitor for
personnel in confined work places. It is self-contained, light
weight and battery operated. It does not require any adjustments
by the user other than routine calibrations. The monitor reads
true percent oxygen in the presence of any diluents including
humidity and will not be affected appreciably by barometric
pressure changes caused by elevation or weather changes.