Generally speaking, the selection of safety gate is easy, not easy to damage, the original system structure requires less changes, and the advantages are obvious. The explosion-proof principle of the safety gate is to control the output voltage with a secondary tube and limit the output current with a resistor. The circuit is relatively simple. In normal operation, the safety gate is equivalent to two resistors in series into the circuit, so there is no need to change the system structure. In addition, the safety grid has no effect on the accuracy of the original signal because there is no signal transformation. The isolated safety gate uses high frequency as the fundamental wave to modulate and demodulate the signal. If the signal changes, the accuracy will be affected by the safety gate circuit.

Due to the high frequency oscillation circuit, the isolation safety gate will produce RF interference, which is unfavorable to the system, and the isolation safety gate is also relatively easy to damage. However, the isolation safety grid does not require intrinsic safety grounding, which is its advantage over the Zener safety grid.