Explosion-proof electric contact pressure gauge according to GB3836.2 83 explosive environment with explosion-proof electrical equipment General requirements for explosive atmospheres flameproof electrical equipment in explosion-proof electrical equipment requirements and relevant standards of the "d" "designed" and GB3836.2 83 " manufacturing drawings and technical documents through the inspection agency designated by the State for approval. Instrument of explosion-proof category ‖ class a flameproof B grade T4 group, the its logo Exd ‖ BT4. The instrument suitability of explosion is used to measure the non-crystalline, non-explosive mixture solidified or no explosive medium pressure. Instrument with the corresponding explosion-proof performance or electrical devices (such as relays and contactors, etc.) supporting the use of automatic control and the purpose of the letter (alarm) will be able to be controlled system to take the appropriate security measures. ■ Main technical indicators: Accuracy class: 1.6 Scale range: 0 to 0.16,0 ~ 0.25, ~ 0.4, 0 - to 0.6, 0 to 1.0, 0 to 2.5, 0 to 4,0 to 6,0 to 10 0 to 16,0 to 25,0 to 40,0 to 60, -0.1 to 0.06 -0.1 to 0.15 -0.1 to 0.3 -0.1 to 0.5 -0.1 to 0.9 -0.1 to 1.5 -0.1 to 2.4MPa. control mode: lower limit put on hold the the contact switch highest operating voltage: DC 220V or AC 380V contact power: 10VA Working position: vertical installation using the environmental conditions: -10 to 50 ℃, relative humidity less than 80%, and explosive mixture should belong to no effect, vibration and measured medium pulse of reliable operation of the instrument from contact ‖ Class B T4 group. Temperature effect: showing the value of not more than 0.4% / 10 ℃, the set-point of not more than 0.6% / 10 ° C (working temperature deviates from 20 ± 5 ℃) Insulation strength: 50Hz sinusoidal AC 2000V lasted one minute weight: 6kg ■ structural principle by flameproof enclosure, measuring systems, electrical contacts group: Instrumentation, adjustment device and the outlet box. Flameproof enclosure of the instrument has good explosion-proof performance, during normal operation due to the impact of a spark or arc, except inside the housing can withstand the explosive gas mixture generated Once explode, explosion pressure and effective prevented the resulting heat is smoothly spread outward, but only in the interior of the housing at a small gap along the flameproof joint Laborers outdiffusion. In this case, the instantaneous temperature of the spread to the outside of the housing has been reduced to below the ignition temperature of the explosive gas mixture, and therefore do not lead to the explosion transfer. Instrumentation work