supply of online chlorine detector , supply of items as per following specifications , supply: 12-30 vdc , 2 wire , signal output: 2 wire , 4 - 20 ma dc , display: 3 1 / 2 digit lcd , intrinsically safe , atex / ul certified , approvals: exia iic t4 , zone 2 / ul class i , groups a , b , c and d , measuring range : 0-10 ppm with accuracy of + / -5% of range or better , enclosure: poly phenylene sulphite or better , ip65 , suitable for 2 stand pipe mounting , acceptable makes: draeger , honeywell , dettronics , msa , bieler + lang , omniguard , spectrex , enmet , monicon , respo only . other makes shall be rejected .