Transducers Direct Introduces TDEPD Pressure Transducer/Switch

March 17, 2015
360-degree marquee display provides visual cues signaling pressure, condition and readiness of a fluid power system.

The TDEPD electronic pressure transducer/switch features a programmable marquee display that can revolve, hold at a fixed angle or be inverted for upside down installations. Selectable red/green display colors allow programming of a variety of visual cues signaling the pressure, condition and readiness of a fluid power system. Coupled with a sub-millisecond update time, Spike Monitoring Technology (SMT) captures and records short-duration "explosions" of hydraulic overpressure to protect the transducer and fluid-power system. SMT records spikes at 120% of rated pressure. The number of spikes and maximum pressure recorded is reviewable on the display using the sensor's programming buttons.

The TDEPD transducer senses pressure using a time-to-digital converter (TDC) to measure the duration of a capacitive discharge across the changing resistance in a Wheatstone bridge atop the diaphragm. Circuitry splits the signal from the bridge, creating duplicate signals that ensure continuous machinery operation if one half should fail. The design eliminates amplifiers, filters, amplified noise and signal delays, producing a high-resolution signal without analog variability or noise in the circuit.

The TDEPD is all-digital with field-selectable, industry-standard outputs. Its circuitry includes redundant sensing elements to ensure continuous machine uptime, while alerting the machine control of the need for replacement. The US-made TDEPD eliminates all mechanical components, wear parts and set point drift for reliability in shock and vibration applications, according to the company. It uses a one-piece, precision-machined stainless steel diaphragm and header. All wetted parts are stainless steel, and the top-mounted connector simplifies wiring installation. Sealed to IP67, it is suited for automotive stamping presses, mobile hydraulic equipment, injection molding machinery, rolling mills, amusement park rides, timber processing equipment and similar applications.

The TDEPD is shock rated to 50G and accurate to within 0.5% of its maximum operating pressure of 10,000 psi (689 bar). It is fully compensated for temperature over its entire operating range of -40°F to 185°F (-40° to 85°C). The TDEPD has one digital output as standard, with an optional analog output of up to 10 VDC or up to 20 mA (field selectable) available. Three configurations are available with one switch output, two switch outputs or one analog output and one switch output. Standard overpressure rating for the TDEPD is 2X, with 4X and 10X optional. Burst pressure is 5X or 20,000 psi, whichever is less. It is available with a variety of industry standard pressure-port connections.