nowadays, in the process of air quality management, the use of VOC detector is very common, because it is the eye of VOC control industry, real-time monitoring of whether the concentration of VOC exceeds the standard, monitoring and control through VOC detector can be significantly improved. However, in the use of VOC detector, sampling is a very important aspect, do a good job of sampling in order to better gas detection. So VOC detector what are the sampling requirements? The following is a brief introduction by yi yun Tian:

The sampling requirements for VOC detector are as follows:

1. The sample taken from the sampling point should be representative and should not cause changes in composition and content after passing through the sampling system. The sampling port shall be set at a place easily accessible to maintenance personnel, and the temperature, pressure and lag time of the sample shall be taken into account; the sampling port shall not be selected in the low velocity area where the fluid is laminar flow and the vortex area and dead angle downstream of the throttling element.

2. The sampling pipeline should be as short as possible to make the lag time. The lag time of the sample delivery system should not exceed 60s. The diameter of the sampling pipe is generally φ6 × 1mm, but the diameter of the sampling pipe shall not be greater than φ14 × 2mm.

3. according to the sampling process of VOC detector, the sampling system should have corresponding functions such as decompression and steady flow, condensate discharge, overpressure venting, negative pressure suction, fault alarm or high temperature resistance.

4. The sampling tube is generally made of stainless steel. If the sample contains components that corrode the stainless steel tube, polyvinyl chloride, polytetrafluoroethylene and other suitable materials can be used. Seamless steel tubes can also be used for non-corrosive dry samples. In addition, anti-blocking measures shall be taken for the sample guide pipeline.

5, gas sample should avoid liquid mixing, liquid sample should avoid entrainment of gas. If the process line pipe wall is prone to dirt, the sampling probe should be inserted into the center of the line. When the sample contains solid particles, the sampling place must be equipped with a filter and a blowback interface.

6. if condensation occurs during the sampling process of VOC detector, heat preservation and heat tracing measures must be taken, but changes in sample composition caused by overheating should be avoided.

To sum up, it is the sampling requirement of VOC detector. The current VOC detector It is the 1 detector widely used in various chemical sites, because this detector has a high accuracy value, is very suitable for air detection, and is also very easy to carry. Especially in the face of emergency, patrol and leak detection, can use the pump suction, this situation highlights its short response time, high sensitivity, more easy to quickly detect the location of the leak point.