Gastec Ammonia Detector Tube features 2 pump strokes and 1/2 correction factor for 0.5 - 1 ppm measuring range, 1 pump strokes and 1 correction factor for 1 - 30 ppm measuring range and 1/2 pump strokes and 2.6 correction factor for 30 - 78 ppm measuring range. Detector tube with sampling time of 45 sec per pump stroke is ideal to detect ammonia in air or the industrial areas and environmental atmospheric condition. Detector with 0.2 ppm detecting limit, changes color from pink to yellow.