Piezoelectric Accelerometer - Endevco

Piezoelectric AccelerometerModels 7722 & 7724• The Ultimate Accelerometer ForCryogenic TemperatureMeasurement• Withstand Repeated ThermalShock Down to -452°F (-269°C)• Wide Bandwidth, ISOSHEAR ®• Hermetically Sealed, TopConnectorActual sizeENDEVCOMODEL77227724DESCRIPTIONThe ENDEVCO ® Models 7722/7724 are ruggedpiezoelectric accelerometers built specifically formeasuring vibration under cryogenic conditions. Signaloutputs of these units are very stable even at extremelylow temperatures. Their internal construction isdesigned to withstand multiple cycles of thermal shockwith steep temperature gradient. The accelerometersare self-generating devices that require no externalpower source for operation.The Models 7722/7724 feature ENDEVCO’sPIEZITE ® Type P-23 crystal elements arranged inISOSHEAR ® configuration. These units exhibit lowbase strain sensitivity and excellent output stability overtime. To achieve high reliability under the mostextreme temperature conditions, no thermal expansion-criticalconnection, (such as wirebond, epoxy orsolder,) is used inside the accelerometer. The Model7722 is a grounded design (ground connects to theouter case), and the Model 7724 is an isolated design(both signal and ground are isolated from the outercase).ENDEVCO Signal Conditioner Models 133, 2775Aor OASIS 2000 Computer-Controlled System are recommendedfor use with these high impedanceaccelerometers.TYPICAL AMPLITUDE RESPONSE20TYPICAL TEMPERATURE RESPONSE20151510CHARGE SENSITIVITY10% DEVIATION50-5% DEVIATIONCAPACITANCE50-5-10-10-15-15-201 10 100 1000 10000FREQUENCY IN HERTZ-20-500 -400 -300 -200 -100 0 100 200 300 400(-296) (-129) (38) (204)TEMPERATURE o F ( o C)APPLIES TO CALIFORNIA FACILITY

ENDEVCOMODEL77227724Piezoelectric AccelerometerSPECIFICATIONSThe following performance specifications conform to ISA-RP-37.2 (1964) and are typical values, referenced at +75°F (+24°C), and100 Hz, unless otherwise noted. Calibration data, traceable to National Institute of Standards and Technology (NIST), is supplied.DYNAMIC CHARACTERISTCSUnitsCHARGE SENSITIVITYTypical pC/g 3.7FREQUENCY RESPONSESee Typical Amplitude ResponseResonance Frequency kHz 20Amplitude Response, [1]±5% Hz 2 to 4000±1dB Hz .5 to 5000TRANSVERSE SENSITIVITY % ≤ 3 (≤ 1 on special order)TEMPERATURE RESPONSESee Typical CurveAMPLITUDE NONLINEARITY [2] % 1Up to vibration limitELECTRICAL CHARACTERISTICSOUTPUT POLARITYAcceleration directed into base of unit produces positive outputRESISTANCE GΩ ≥ 10ISOLATION MΩ ≥ 100CAPACITANCE pF 120GROUNDINGModel 7722Signal return connected to caseModel 7724Signal return isolated from caseENVIRONMENTAL CHARACTERISTICSTEMPERATURE RANGE-452°F to +350°F (-269°C to +177°C)HUMIDITYHermetically SealedSINUSOIDAL VIBRATION LIMIT g pk 500SHOCK LIMIT g pk 2500BASE STRAIN SENSITIVITY equiv. g pk/µ strain 0.0008THERMAL TRANSIENT SENSITIVITY equiv. g pk/°F (°C) 0.001 (0.002)ELECTROMAGNETIC SENSITIVITY equiv. g rms/gauss 0.0003PHYSICAL CHARACTERISTICSDIMENSIONSSee Outline DrawingWEIGHT gm (oz) 29 (1.0)CASE MATERIALStainless SteelCONNECTOR10-32 UNF-2A Thread mates with Endevco Model 3090C Cable or equivalentMOUNTING TORQUE lbf-in (Nm) 18 (2)CALIBRATIONSUPPLIED:CHARGE SENSITIVITYpC/gMAXIMUM TRANSVERSE SENSITIVITY %CAPACITANCEpFFREQUENCY RESPONSE % 20 to 4000 HzdB4 kHz thru resonanceACCESSORIESModel 3090C-120 (10 ft) CABLE ASSEMBLYModel 2981-12 MOUNTING STUD, 10-32 to 10-32EHM464HEX KEY WRENCHOPTIONAL ACCESSORIESModel 2981-4MOUNTING STUD, 10-32 to M5Model 2771AM3 IN-LINE CHARGE CONVERTOR FORUSE WITH CONSTANT CURRENTSOURCEModel 2950TRIAXIAL MOUNTING BLOCKNOTES1. Low-end response of the transducer is a function of itsassociated electronics.2. Short duration shock pulses, such as those generated by metalto-metalimpacts, may excite transducer resonance and causelinearity errors. Send for TP290 for more details.3. Maintain high levels of precision and accuracy using Endevco'sfactory calibration services. Call Endevco’s inside sales force at800-982-6732 for recommended intervals, pricing and turnaroundtime for these services as well as for quotations on ourstandard products.Optional In-Line Charge Convertor, Model 2771AM3Continued product improvement necessitates that Endevco reserve the right to modify these specifications without notice. Endevco maintains a program of constantsurveillance over all products to ensure a high level of reliability. This program includes attention to reliability factors during product design, the support ofstringent Quality Control requirements, and compulsory corrective action procedures. These measures, together with conservative specifications have made thename Endevco synonymous with reliability.ENDEVCO CORPORATION, 30700 RANCHO VIEJO ROAD, SAN JUAN CAPISTRANO, CA 92675 USA (800) 982-6732 (949) 493-8181 fax (949) 661-7231www.endevco.comEmail:applications@endevco.com0101