what are photohelic gauges
Dwyer Series A3000 PhotohelicÂ® Pressure Switch/Gauge. PhotohelicÂ® Switch/Gages function as versatile, highly repeatable pressure switches combined with a precise pressure gage employing the time-proven Magnehelic Â® gage design. The PhotohelicÂ® gage measures and controls positive, negative or differential pressures of air and compatible gases. Standard models are rated to 25 psig (1.7 bar) with options to 35 (2.4) or 80 (5.5 bar) psig. Single pressure 36000S models measure to 6000 psig (413 bar) with a 9000 psig (620 bar) rating.