The EC91 is an on-line transmitter for ppm and percent oxygen measurements of gas streams in hazardous area installations. It is approved for use in EEx ia IIc T4 - Zone 0 areas (ATEX approved). It can detect oxygen levels from 1 ppm to 21.0% and can be used in most industrial gases and atmospheres. The instrument requires no periodic maintenance such as replacing electrodes or electrolyte and is easily calibrated using ambient air or standard calibration samples. The enclosure is molded of glass fibre reinforced polyester, an impact resistant material unaffected by oils, common acids, and alkalies. A wide door is fitted with stainless steel hinge pins making it suitable for harsh environments and protected to IP65 standards.
The Model EC91 is wall mounted and transmits a 4-20mA signal corresponding to the oxygen level. The unit may have up to six ranges and has an LCD display for local indication. An optional control room display and alarm unit is also available. All electronic circuits are intrinsically safe and have been certified to BASEEFA and CENELEC standards. Connections to safe areas must be fitted with shunt diode safety barriers.