Measured value can be read-off directly and immediately via colour indication. It consists of sampler pump and tubes. A wide variety of tubes are available, applicable to the gas being tested. The most common tubes are discussed below.
测量值可通过颜色指示直接、即时读出。它由取样器、泵和管子组成。可供选择的管子种类繁多,适用于所测试的气体。下面讨论最常见的管子。