Tiandi and the explanation of the terminology of gas detectors: For the general terminology of gas detectors, whether it is a portable gas detector or a stationary gas detector, we should know some common technical terms, which will provide us with a great convenience in selecting a gas detector. 1.ppm (parts per million by volume) - is the most common unit of measurement used by gas detectors to detect toxic gases. 10,000ppm=1%vol 2. LEL (Low Explosive Limit) - The minimum flammable gas concentration that can cause an explosion in space. %LEL is the most common unit of detection for detecting combustible gases. 3. IDLH (value that immediately poses a hazard to human health)—The maximum concentration of toxic gas that a worker can safely evacuate from the site without being exposed to poison gas within 30 minutes. The IDLH value is measured in ppm. 4. PEL (Permitted Exposure Limit) - Allows the worker to repeatedly expose exposure to this concentration for 8 hours per day, 40 hours per week, and is not threatened by toxic gases. PEL values ​​are measured in ppm 5. UEL (Highest Explosive Limit) - The highest flammable gas concentration that can cause an explosion in space. A flammable gas above this concentration will result in a lack of oxygen in the space and will not cause an explosion in the space. 6. Anoxic state—The state in which the oxygen content in the air is less than 19.5% vol is called the anoxic state (this state will cause difficulty in human breathing). The oxygen state—the state in which the oxygen content in the air is higher than 22% vol. (This state will increase the likelihood of an explosion in space) Cross Sensitivity—Because the sensor's output is determined by the chemical reaction that occurs, this can cause other gases besides the sensor's corresponding detection gas to react to the sensor and The meter produces a certain degree, which is the cross sensitivity. 7. TLV (Critical Limit Value)—The reference value of the concentration of harmful gases exposed to the daily working hours that the worker can withstand. There are currently three critical limits: 1) TLV-TWA (weighted average): The concentration-weighted average of the concentration of harmful gases in the environment allowed by workers for 8 hours/day of normal exposure. 2) TLV-C (highest limit value): The highest limit value concentration that the worker may be exposed. This value is the highest value and cannot be exceeded. The state takes precedence over the TWA and STEL values. 3) TLV-STEL (short-term exposure value): The worker is exposed to harmful gases for a short time (15 minutes) and will not cause harm to the person. A limit concentration time-weighted average of evacuation self-rescue can be performed. Such limits cannot occur more than four times a day, and the time interval between each must be greater than 60 minutes. A Knife And Fork Frame,Fork Frame,Knife And Fork Frame,Knife Frame ningbo haonuo hardware factory , https://www.haonuocrafts.com