Manufacturers Embrace Latest Intrinsic Safety Standard for Land Mobile Radios

First LMR certified under FM Approvals’ revised intrinsic safety standard



Two-way radios—also known as land mobile radios (LMRs)—intended for commercial, professional or governmental use must be rugged, reliable and easy to use in a wide range of challenging situations and environments. For many applications, particularly fire, rescue, petrochemical, pharmaceutical, utilities and the gas industry, LMRs must also be certified for use in hazardous (classified) locations where a risk of fire or explosion can exist.


The FM Approvals standard, FM 3610, Intrinsically Safe Apparatus and Associated Apparatus for Use in Class I, II and III, Division 1, Hazardous (Classified) Locations, has been the key safety certification benchmark for LMRs since 1967. As with all Approval standards, FM 3610 has been updated over the years to keep pace with technological innovations and to maintain an acceptable margin of safety.  FM 3610 was last updated in December 2015, with an effective date of January 1, 2017, to comply with the latest U.S. national standard: ANSI/ISA-60079-11 2014. 


LMR manufacturers also have the opportunity to obtain FM Approvals certification for their products under Approval Standard 3640, Land Mobile Radios for Use in Class I, Division 1 Hazardous (Classified) Locations, which encompasses intrinsic safety (FM 3610), but also provides other protection options (see related story).


First to be FM Approved under new intrinsic safety standard

Last April, Hytera Communications Corporation Limited introduced the industry’s first LMR to obtain FM Approvals certification under the new FM 3610 intrinsic safety standard. The new Hytera PT790 Ex is certified by FM Approvals to not only be intrinsically safe under FM 3610, but is also ATEX- and IECEx-certified. Hytera worked with FM Approvals on all three certifications.


“When we announced we were working on a radio that could meet tough new standards for intrinsic safety, others in the LMR industry doubted us,” notes Gee Siong (“GS”) Kok, senior vice president and general manager of engineering for Hytera. A 30-year veteran of the LMR industry, GS was born and raised in Malaysia, went to college in the United Kingdom and now heads Hytera’s 600-engineer multinational design group.



“The resolve and perseverance of our research and development team has resulted in the first radio to be certified by FM Approvals under the new intrinsic safety standard,” GS says. “We have set the bar high for others in our industry. The reception among our distributors and customers has been amazing. We had offers to engage other testing agencies, but I have been in this industry for 30 years and I know whom I should be partnering with. I felt FM Approvals was the best choice because they are a global presence and a trusted brand. Their ability to provide multiple certifications, of course, saves time and money.”


According to FM Approvals’ electrical systems group manager, Jim Marquedant, “Our intrinsic safety standard has been, and still is, FM 3610. While we have aligned it with current U.S. and international standards, it does not in any way unduly limit the power or potential power of handheld radios. We are aware that some LMR makers have been reluctant to embrace the most up-to-date intrinsic safety standards, and we encourage them to do so. We are pleased that one major radio maker—Hytera—has already earned certification in accordance with the latest version of FM 3610 and we expect many more to follow. Hytera has shown that through a diligent and dedicated engineering effort, it is not only possible to meet the latest intrinsic safety standards, but to do so without compromising radio performance. They did what some manufacturers dismissed as not possible, and as a result, will likely benefit in the marketplace.”

Hytera’s GS adds, “I like the fact that FM Approvals challenges us. They are very professional and very stringent, which is critical in order to provide the safest possible LMR. We had to work hard to earn the FM Approvals certification, but it’s been worth it because it is a quality mark that is recognized around the world.”