A design route for an intrinsically safe gas-meter power source: comparing Li-SOCl2, Li-MnO2, a NiMH pulse reservoir, supercapacitor and Li-ion, budgeting the ten-year current and the valve pulse, and designing within ATEX energy limits.
The battery duty of an ATEX smart gas meter under EN 1359 and OIML R137 - years of microamp sleep, daily NB-IoT reporting and an occasional but safety-critical motorised shut-off valve pulse - and the role of a NiMH pulse reservoir.
The validation matrix behind a ten-year meter battery: ISO 4064 and OIML R49 metrological continuity, MID type examination, IP68 ingress, IEC 62133-1 cell safety, UN 38.3 transport and a pulse-cycling and ageing programme for a NiMH pulse-assist layer.
A design method for the meter power source: comparing Li-SOCl2, Li-MnO2, a NiMH pulse-assist hybrid, supercapacitor and rechargeable Li-ion, building the microamp-to-milliamp energy budget, and sizing the pulse reservoir for NB-IoT and valve loads.
The extreme duty cycle of an IP68 smart water meter under ISO 4064 and OIML R49 - years of microampere sleep, millisecond measurements and brief radio bursts - and where a NiMH pulse-assist cell fits beside the primary lithium battery.
The validation matrix for a 24 V NiMH control-rail backup: IEC 61131-2 equipment and interruption tests, IEC 61000-4-11 voltage dips and interruptions, IEC 60204-1 machine supply, plus IEC 62133-1, IEC 61951-2 and a standby-fade programme.
A design method for a 24 V control-rail backup: comparing NiMH with supercapacitor, lithium and the internal capacitor, calculating hold-up energy for graceful shutdown and last-gasp, and designing the blocking, charge and protection topology.
Why a programmable controller's internal capacitor only covers a few milliseconds of mains loss under IEC 61131-2, and how a NiMH 24 V backup module extends ride-through enough to save retentive data and send a fieldbus last-gasp.
