Scientific TMX412 Gas Monitors for confined space air testing. Hazardous gas monitors are calibrated by factory trained personnel. Same day shipping available. TMX412 rental meters.... now makes it unnecessary to purchase and maintain gas monitoring equipment for those semi-annual jobs where gas monitoring is required. TMX412 rentals for $99.00 / Week and $300.00... / Month. Only $99.00 for a weekly TMX412 gas meter rental with everything included to perform your air monitoring including sample pump, sample tubing, nicad batteries and battery...