In gas detection, a device that draws an air sample into a detecting agent (colorimetic gas sampling tube or gas detector). Colorimetric gas sampling tubes require a pump, manual or electronic, to draw a sample through them. For electronic gas detectors, pumps can be integrated, clip-on or hand aspirators. Gas detectors with an integrated pump are suitable to sample confined spaces for gas hazards through a sampling hose. Photo Ionisation Detectors (PID) should always be equipped with a pump. A pump generally shortens the response time to gas hazards, but also consume electricity, shortening the battery life.