A surge suppressor kit now is available for use with Moore Industries’ field-installed instruments enclosed in its BH and SB housings. The kit is approved for use in explosion-proof applications in the U.S./Canada (sCSAus) and Australia/New Zealand (ANZEx). The surge suppressor exceeds Severity Level 4 of IEC 61000-4-4, providing 3 kA (8/20 μsec) of surge protection stopping failures from lightning, spikes and overvoltage surges while minimizing other electrical noise. This suppressor allows HART signals to pass through and therefore can be used to suppress or protect both analog and HART digital/analog signal lines.