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Eight kinds of common explosion-proof types for instrumentation-focusing on microfluidic control technology

Instrumentation often involves an explosion protection problem because explosion protection is required in some special working environments and some special-purpose instruments and meters. For example, electrical hazards, instrumentation equipment, trunking, cable trenches, and explosion-proof instrument panels (boxes) for explosion-risk areas should all be explosion-proof. What are the common explosion protection types for instrumentation?
In general, explosion-proof types basically include explosion-proof type “d”, increased safety type “e”, positive pressure type “p”, intrinsically safe type “i”, oil-immersed type “o”, and sand-filled type “q”. , Encapsulation type "m", dust proof type and so on.
Classification analysis
1, flameproof type "d"
Flameproof type "d" Explosion-proof type refers to the parts in the explosion-proof enclosure that may generate sparks, arcs and dangerous temperatures. The internal space of the equipment is separated from the surrounding environment by the flameproof enclosure. There is a gap in the flameproof enclosure. When an explosion occurs inside the enclosure, the enclosure can withstand the explosion pressure generated without damage, so that the flame or dangerous flame products cannot ignite the external explosive environment.
2. Increased safety "e"
Increased safety type is to take some additional measures to make the electrical equipment that will not produce arcs or sparks under normal operating conditions more secure. Generally, measures are taken to reduce or control the operating temperature, ensure the reliability of the electrical connection, increase the insulation effect, and increase the degree of protection of the enclosure.
3, positive pressure type "p"
The positive pressure type explosion-proof type is to keep the pressure of the protective gas inside the device shell higher than the surrounding explosive environment pressure in order to achieve safety. Positive pressure equipment protection types include protecting static positive pressure inside the system and holding continuous air or inert gas flow to restrict flammable mixtures from entering the interior of the enclosure.
Intrinsically safe type "i"
The intrinsically safe explosion-proof type is an intrinsically safe circuit in which all circuits inside the device cannot ignite a prescribed explosive gas atmosphere by any spark or any thermal effect produced under the conditions specified in the standard. Mainly by limiting the energy in the circuit, through the reliable control of the circuit parameters to reduce the potential spark energy to ignite the specified gas mixture energy.
5, oil-immersed type "o"
The oil-immersed explosion-proof type is to immerse the whole equipment or the components of the equipment in the oil (protection fluid) so that it cannot ignite the explosive gas atmosphere above the oil surface or outside the housing.
6, sand filling "q"
The sand-filled type explosion-proof type is a kind of powdered material filled with sand or other specified characteristics in the outer shell, so that the electric equipment protection type in which the arc or high temperature generated inside the shell cannot ignite the surrounding explosive gas atmosphere under the specified use conditions.
7, sealing type "m"
The encapsulated type explosion-proof type is an electrical component that may generate a spark, an arc, or a dangerous temperature portion that may cause explosion of an explosive mixture, and is encapsulated in a potting compound (composite) so that it cannot ignite the surrounding explosive mixture.
8, dust explosion-proof type
Dust explosion-proof electrical equipment is used to limit the shell surface temperature and the use of "dust-tight" or "dust-proof" enclosure to limit the entry of dust to prevent ignition of flammable dust.

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