Model 2271A / AM20 Piezoelectric accelerometer Features Description ® • NEW! 2271A-R available as replacement sensor The Endevco model 2271A/AM20 is a wide temperature range piezoelectric accelerometer designed to measure • Low temperature operation vibration in cryogenic temperature applications. The • Hermetically sealed unit is hermetically sealed and is ideal for use in • Ground isolated extreme environmental conditions. This accelerometer • Flat temperature response (-269°C to +260°C) offers an unusually flat temperature response into a • Vibration at cryogenic temperatures wide temperature range. The accelerometer is a self generating device that requires no external power source for operation. ® Model 2271A/AM20 features Endevco’s Piezite type P-10 crystal element operating in compression mode. This unit exhibits excellent output sensitivity stability over time. Signal ground is isolated from the outer case of the unit. The 2271A features a 10-32 side-connector and the 2271AM20 has a 10-32 top connector. A low-noise coaxial cable is supplied for error-free operation. Endevco signal conditioner models 133, 2771C, 2775B or OASIS 2000 computer- controlled system are recommended for use with these high impedance accelerometers. TYPICAL TEMPERATURE RESPONSE 30 .625 HEX 25 (15.88) 20 CAPACITANCE 15 10 .62 DIA MATES WITH ENDEVCO (15.8) 5 3000 SERIES CABLES WITH 10-32 UNF-2B CONNECTOR 0 -5 .021 (.53) DIA CHARGE SENSITIVITY SAFETY WIRE HOLES -10 -15 UNIT IDENTIFICATION -20 1.15 10-32 UNF-2B THD (29.2) -400 -300 -200 -100 0 100 200 300 400 500 .98 (-240) (-129) (-18) (38) (149) (260) (24.9) .035 (.89) DIA SAFETY WIRE HOLES TEMPERATURE ϒF (ϒC) .46 (11.7) .117 MIN THD (2.97) TYPICAL AMPLITUDE RESPONSE 20 .250 DIA .030 15 (6.35) (.76) .540 DIA .010 (.25) 10 (13.72) .005 (.13) NOTE: IF ALTERNATE STUD IS USED, THE LENGTH OF STUD FROM MOUNTING 5 SURFACE MUST BE .155/.135 (3.94/3.43). STANDARD TOLERANCE 0 INCHES (MILLIMETERS) .XX = +/- .03 (.X = +/- .8) .XXX = +/- .010 (.XX = +/- .25) -5 -10 -15 2271A 2271AM20 -20 110 100 1000 10000 FREQUENCY IN HERTZ % DEVIATION % DEVIATION Model 2271A / AM20 Piezoelectric accelerometer Specifications The following performance specifications conform to ISA-RP-37.2 (1964) and are typical values, referenced at +75˚F (+24˚C), 4 mA and 100 Hz, unless otherwise noted. Calibration data, traceable to National Institute of Standards and Technology (NIST), is supplied Dynamic characteristics Units Value Charge sensitivity Typical pC/g 11.5 Minimum pC/g 10 Frequency response See typical amplitude response Resonance frequency kHz 27 Amplitude response [1] ±5% Hz 2 to 4000 ±1 dB (ref) Hz 1 to 8000 Temperature response [3] See typical curve Transverse sensitivity % ≤3 Amplitude linearity % 1 Per 1000g, 0 to 10 000 g Electrical characteristics Output polarity Acceleration directed into base of unit produces positive output Resistance GΩ ≥10 Resistance at +500°F (+260°C) MΩ ≥100 Isolation GΩ 1 Capacitance pF 2000 Grounding Signal return isolated from case Environmental characteristics Temperature range -452˚F to +500˚F (-269˚C to +260˚C) Humidity Hermetically sealed Sinusoidal vibration limit g pk 1000 Shock limit [2] g pk 10 000 Base strain sensitivity equiv. g pk/μstrain 0.002 Electromagnetic sensitivity equiv. g rms/gauss 0.0003 Physical characteristics Dimensions See outline drawing Weight gm (oz) 27 (0.95) Case material Stainless steel Connector 10-32 UNF-2A Thd mates with Endevco 3000 2271A side-connector series cable or equivalent 2271AM20 top-connector Mounting torque lbf-in (Nm) 18 (2) Calibration Supplied: Frequency response % 20 Hz to 6000 Hz dB 6 kHz to 40 kHz Sensitivity pC/g Maximum transverse sensitivity % Capacitance pF Model 2271A / AM20 Piezoelectric accelerometer Accessories: Product Description 2271A/AM20 2271A-R 3090C-120 Cable assembly, 10 ft Included Optional 2981-2 Mounting stud, 10-32 to 10-32 Included Included EHM464 Hex key wrench Included Optional 2981-4 Mounting stud 10-32 to m5 Optional Optional 2771C In-line charge converter Optional Optional 2950 Triaxial mounting block Optional Optional 133 Signal conditioner Optional Optional 2775B Signal conditioner Optional Optional 4990A-X OASIS 2000 computer-controlled system Optional Optional Notes: 1. Low-end response of the transducer is a function of its associated electronics. 2. Short duration shock pulses, such as those generated by metal-to-metal impacts, may excite transducer resonance and cause linearity errors. Send for TP290 for more details. 3. Exposure to rapid temperature change greater than 100°F (38°C) per minute may cause the device to produce spurious high frequency discharges for several minutes. 4. Maintain high levels of precision and accuracy using Meggitt’s factory calibration services. Call Meggitt’s inside sales force at 800-982-6732 for recommended intervals, pricing and turn-around time for these services as well as for quotations on our standard products. Continued product improvement necessitates that Meggitt reserve the right to modify these specifications without notice. Meggitt maintains a program of constant surveillance over all products to ensure a high level of reliability. This program includes attention to reliability factors during product design, the support of stringent Quality Control requirements, and compulsory corrective action procedures. These measures, together with conservative specifications have made the name Meggitt synonymous with reliability. ©Meggitt (San Juan Capistrano), Inc. All Rights Reserved 30700 Rancho Viejo Road, San Juan Capistrano, CA 92675 USA APPLIES TO CALIFORNIA FACILITY (800) 982-6732 • (949) 493-8181 fax (949) 661-7231 • www.endevco.com • Email: applications@endevco.com 100812