The Hengstler Type 497 series is a range of pneumatic preset counters and timers, built for panels where an electrical counter either isn’t practical or isn’t allowed, such as areas with explosive atmospheres (ATEX-rated models are available). Within the series, you can get adding counters, subtracting counters, or time counters (in minutes and seconds), all sharing the same basic mechanical platform.
Displays come in 3-digit or 5-digit versions, with the preset value staying permanently visible on some versions rather than disappearing once counting starts. Reset can be a manual pushbutton, an integrated pneumatic reset, or automatic reset, and installation is straightforward through a hose coupler or rapid-fit connector. Typical operating pressure is 2 to 8 bar, and protection class is IP40 as standard, with higher protection available via covers.
From our experience, this series gets specified wherever a simple, rugged, non-electronic preset counter is preferred over an electronic one, especially in hazardous areas. Before we quote a specific part number from this series, we would normally check digit count, counting mode (adding, subtracting, or time), reset type, and whether you need the standard or ATEX-rated version. Hope this helps.
