Siemens 547-002 Differential Pressure Monitor Without Key switch Brand new/ opened box to take photos and verify contents SIEMENS 547-002 is a Differential Pressure Monitor (DPM) used to monitor room or duct pressure, typically in critical environments like cleanrooms, labs, or isolation spaces.? What it is Siemens 547-002 is a wall-mounted differential room pressure monitor in the APOGEE/Building Technologies line, not a general-purpose field controller or VFD.? It works with one or two remote pressure transmitters to display and supervise room pressure relative to a reference space (positive, negative, or neutral depending on setup)."? Key features Monitors low differential pressures (on the order of fractions of an inch of water column) and can output a 4?20 mA signal proportional to measured pressure.? Provides local display, alarm indication (including audible horn and horn silence), and alarm relay output for integration with building automation or external alarms.? Communicates over the Siemens FLN/LAN so it can be supervised by a Siemens field panel or building automation system.? Model specifics 547-002 is the base DPM variant; related part numbers (547-005/547-006) add keyed switches and are configured specifically for negative or positive pressurization applications.? The unit is powered from 24 Vac (typical operating range 18?28 Vac) and mounts in a wall box with a front user interface panel. We are wholesaler/liquidators. We bought this in a lot of new items to resell. We are counting upon you to know what you are buying and if this item will suit your needs. Please only purchase this if you agree to those terms. *** PLEASE NOTE! Our store buys and sells a variety of new and used electronics, instruments, tools, antiques and many other items. We do our absolute best to thoroughly test all our merchandise and accurately describe and depict any flaw or defect we find. SHELF:48 SA