A standard Uniphos gas detector tube system consists of two parts viz. the gas detector tube and a piston and barrel type air sampling pump ASP-40. Together they form a Uniphos gas detector system. Ideally for accurate measurements the standard air sampling pump ASP- 40 supplied by the manufacturer is to be used, which comes with five years of warranty. However for marine applications like ship fumigation, where the costly air sampling pump is likely to be misplaced or lost, "use and throw" type of pumps ASP-11 are used. It also draws 100 ml of air at least for a few samplings. However it is subject to very fast wear and tear and hence it is recommended to test it for leaks before every sampling and should be used with caution. 1. Break both ends of the tube using tip cutter. 2. Insert one end of the tube securely in the rubber tube connector ensuring that the arrow on the detector tube points towards the pump. 3. Align the metallic locking pin on the shaft with the slot of the stopper. 4. Pull the pump handle for a full stroke (100 cc), and rotate the handle right or left 90 degree for locking the piston in the slot of the stopper. 5. The target gas concentration is directly obtained on the detector tube scale.