Tender For corrigendum : supply of 8170157523 - portablegasdetector for h2s , serv - 1st year warranty charges for h2s detector , serv - 2nd year pwcamc charges for h2s detector , serv - 3rd year pwcamc charges for h2s detector , 8170156854 - portable nh3 gasdetector f 1-50 deg c , serv - 1st year warranty charges for nh3 detector , serv - 2nd year pwcamc charges for nh3 detector , serv - 3rd year pwcamc charges for nh3 detector