METHOD OF INTRINSIC SAFETY PROVISION FOR PORTABLE INSTRUMENTS Russian patent published in 2008 - IPC E21F9/00 F21L23/00 

FIELD: physics.

SUBSTANCE: invention is related to method of intrinsic safety provision for portable instruments, which are used in mines that are dangerous by gas or dust content, and in highly explosive premises of enterprises of chemical, oil, gas and other industries. Method is based on establishment of safe parameters of power supply source, connection cable and inductive and capacitance loads. At that outlet of autonomous power supply source is shunted by voltage reference diode, stabilisation voltage of which is more than power supply source electromotive force, but less than minimum voltage of arc ignition, short circuit current of power supply source I_sc is measured, limiting resistance R_lim is connected serially with power supply source for reduction of short circuit current twice down to 0.5 I_sc and by characteristics of intrinsic safety I_"в"=F(L, E) for current 0.5 I_sc and electromotive force of power supply source E safe value of inductance L_s is determined, as well as safe value of time constant of connection cable τ_bshr=L_s/R_lim, then inductive load is connected to power supply source. Current is measured in circuit I_l and by characteristics of intrinsic safety I_"в" =f(L, E) for current I_l and electromotive force of power supply source safe value of load inductance L_l is determined and safe value of time constant of inductive load τ_l=L_l/R_l, besides, by characteristics of intrinsic safety U_"в"=f(R, C) for total value of ohm resistances of power supply source and connection cable and for electromotive force of power supply source safe value of load total capacitance is determined.

EFFECT: increase of technical and economic parameters of portable instruments.

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