LVDT Linear Position Sensors PGHD Series Power

Alliance Sensors PG Series LVDT linear position sensors are designed and engineered specifically for steam turbine valve position control system applications in electric power plants. Many of the features incorporated in the design were actually requested by power generation controls engineers. PG sensor models include the PGHD Heavy Duty LVDT and the PGSD Super Duty LVDT. Both PG versions are available on special order as mild radiation resistant for operation in BWR nuclear power plants. The PG Series LVDT linear sensors are heavy duty, from the wire connection terminal block inside an IP-68 sealed heavy wall housing to the 3/8 inch outside diameter core rod in which the LVDT core is encased so that it can never vibrate loose or break off. A pair of double contact shaft seals for the core rod keep dirt and water out of the sensor’s bore. An in-line ball joint coupling on the core connecting rod to take up minor installation misalignment is optionally available, along with other installation hardware such as hold-down clamps, threaded core extension rods, swivel rod eye ends, and mounting flanges. Electrical connections utilize a screw-clamp terminal block for 24 to 14 AWG wires that feed through a 3/4 inch conduit hub outfitted with a 1/2 inch conduit adapter. User-installable connectors are available.

Features

•     Core is enclosed in 3/8 inch (9.5 mm) diameter rod... cannot vibrate loose or break off
•     Dual redundant double contact shaft seals keep contaminants out of LVDT’s bore
•     Works in 3-wire, 4-wire, 5-wire, 6-wire, and ratiometric (A-B)/(A+B) systems
•     Operates to 350°F (175 C) with over-temperature indicator built in
•     Screw clamp terminal block accepts 24 to 14 AWG wires
•     2 year warranty... twice the industry standard

Specifications

• Excitation Frequency     :     3 kHz nominal
• Excitation Voltage          :     3 V ACrms nominal
• Full Scale Output           :     0.9 V ACrms output (nom.) from differentially connected (S1-S2) secondaries with 3 Vrms excitation; sum of secondaries output is constant over range for ratiometric (S1-S2)/(S1+S2) operation
• Linearity Error               :     ±0.3% of FSO nominal, ±0.5% of FSO max
• Operating Temperature  :     -40 to 175 C (-40 to 350 ̊F)
• Temperature Coefficient :     ≤ 0.025% FSO/degree C
• Shock                           :     1000 g, 11 msec
• Vibration                       :     5-20 Hz, 0.5 inch p-p; 20-2000 Hz, 4.2 g p-p