Variable Capacitance Accelerometer ENDEVCO Model 7596A MODEL 7596A • • • • • Economical and Rugged 2 to 100 g Full Scale DC Response Gas Damped Sensor Mechanical Over-range Stops DESCRIPTION The ENDEVCO Model 7596A VALULINE accelerometer family is a low cost solution to low-level, low frequency measurements. Applications include laboratory measurements, ground transportation studies and measurements where the accelerometer will be subjected to high shock levels (up to 10 000 gs, see specifications). The 7596A is ideal for modal studies on large structures. Actual size Gas damping and internal overange stops enable the anisotropically etched silicon microsensors to withstand high shocks and acceleration loads. The use of gas damping, in the sensor, results in very small-induced changes of frequency response. The patented sensor design ensures immediate stability making the unit ready to take accurate DC or dynamic data within one millisecond! The 7596A can operate from 8.5Vdc to 30Vdc and provide a high level, low impedance output. The output is high enough to drive most laboratory instruments, tape recorders and data acquisition systems without amplification or signal conditioning. The output can be fed into either a differential or single-ended amplifier or standard bridge electronics with 10Vdc excitation. ENDEVCO Model 136 Three-Channel System, Model 4430A or OASIS Computer-Controlled System are recommended signal conditioners. SPECIFICATIONS PERFORMANCE CHARACTERISTICS: All values are typical at +75°F (+24°C) and 15 Vdc excitation unless otherwise stated. Calibration data, traceable to the National Institute of Standards, (NIST), is supplied. RANGE SENSITIVITY (at 100 Hz) [1] [2] FREQUENCY RESPONSE (± 5%) MOUNTED RESONANCE FREQUENCY NON-LINEARITY AND HYSTERESIS [3] TRANSVERSE SENSITIVITY [4] ZERO MEASURAND OUTPUT [2] DAMPING RATIO DAMPING RATIO CHANGE From -65°F to +250°F ( -55°C to +121°C) Units g pk mV/g Hz Hz % FSO Typ % FSO (Max) % Typ mV Max %/°F %/°C 7596-2 ±2 1000 ±100 0 to 15 1300 ±0.20 ±0.50 1 ±200 3.0 +0.04 +0.08 APPLIES TO CALIFORNIA FACILITY -10 ±10 200 ±20 0 to 500 3000 ±0.20 ±0.50 1 ±200 0.7 +0.04 +0.08 -30 ±30 66 ±8 0 to 800 5500 ±0.20 ±0.50 1 ±200 0.7 +0.04 +0.08 -50 ±50 40 ±4 0 to 1000 5500 ±0.2 ±0.5 1 ±200 0.6 +0.04 +0.08 -100 ±100 20 ±2 0 to 1000 6000 ±1 ±2 1 ±200 0.6 +0.04 +0.08 ENDEVCO Variable Capacitance Accelerometer MODEL 7596A SPECIFICATIONS—continued PERFORMANCE CHARACTERISTICS—continued Units 7596-2 -10 THERMAL ZERO SHIFT From 32°F to 122°F (0°C to 50°C) % FSO Max ±2.0 ±2.0 From -13°F to +167°F (-25°C to +75°C) % FSO Max ±4.0 ±4.0 From -65°F to +250°F (-54°C to +121°C) % FSO Max ±6.0 ±6.0 THERMAL SENSITIVITY SHIFT From 32°F to 122°F (0°C to +50°C) % Max ±2.0 ±2.0 From -13°F to +167°F (-25°C to +75°C) % Max ±4.0 ±4.0 From -65°F to +250°F (-54°C to +121°C) % Max ±6.0 ±6.0 THERMAL TRANSIENT ERROR Equiv. g/°F < 0.0006 < 0.0006 PER ISA RP 37.2 Equiv. g/°C < 0.001 < 0.001 OVERRANGE (Determined by Electrical clipping or Mechanical stops, whichever is smaller.) Electrical clipping g -3.5/+3.8 -18/+19 Mechanical stops, typical g ±4 ±30 Recovery Time µs < 10 < 10 THRESHOLD (RESOLUTION) [5] Equiv. g’s 0.0005 0.0025 BASE STRAIN SENSITIVITY, MAX [6] Equiv. g’s 0.01 0.01 MAGNETIC SUSCEPTIBILITY [7] Equiv. g’s <1 <1 WARM-UP TIME (to within 1%) ms 10 10 ELECTRICAL EXCITATION [2] CURRENT DRAIN [8] OUTPUT IMPEDANCE/LOAD RESIDUAL NOISE ISOLATION PHYSICAL CASE, MATERIAL/BASE ELECTRICAL, CONNECTIONS MOUNTING/TORQUE WEIGHT ENVIRONMENTAL ACCELERATION LIMITS (in any direction) Static Sinusoidal/Random Vibration Shock (half-sine pulse) Zero Shift TEMPERATURE Operating Storage HUMIDITY/ALTITUDE ESD SENSITIVITY -30 -50 -100 ±2.0 ±4.0 ±6.0 ±2.0 ±4.0 ±6.0 ±2.0 ± 4.0 ± 6.0 ±2.0 ±4.0 ±6.0 < 0.0006 < 0.001 ±2.0 ±4.0 ±6.0 < 0.0006 <0.001 ±2.0 ±6.0 ± 6.0 < 0.0006 < 0.001 -53/+57 ±90 < 10 0.008 0.01 <1 10 -87/+95 ±200 < 10 0.0012 0.01 <1 10 -175/+190 ±200 < 10 0.025 0.01 < 0.1 10 8.5 to 30 Vdc, 32 Vdc maximum without damage; excitation voltage can be applied to any lead without damage 4.5 mA Typ, 8 mA Max 50 ohms max/10K ohms resistance minimum, 0.1 µF capacitance maximum 100 µV rms typ, 0.5 to 100 Hz. 500 µV rms typ, 0.5 Hz to 10 KHz 100 MΩ Anodized Aluminum Alloy 28 AWG silver plated alloy 135, PFA340 Teflon® insulated conductors, spiral shield (SPC), HyperFLEX jacket with TFE non-fray, end grip 30 ± 3 inches (760 ± 76mm) long. Two 4-40 x 3/8 6 lbf-in (0.7 Nm) 10 grams (cable weighs 9 grams/meter) 20 000 g 100 g pk, 20 - 2000 Hz/40 g rms, 20 - 2000 Hz 5000 g, 150 µsec or longer for the -2 and -10; 10 000 g, 80 µsec or longer for the -30 and -100 0.1% FSO typical at 5000 g -65°F to +250°F (-55°C to +121°C) -100°F to +300°F (-73°C to +150°C) Unaffected. Unit is epoxy sealed. Hybrid and sensor are hermetically sealed/unaffected. Unit meets Class 3 requirements of MIL-STD-883 CALIBRATION DATA SUPPLIED (noted on shipping box) SENSITIVITY (at 5 Hz and 1 g pk, for 2 g range) (at 100 Hz and 10 g pk, all other ranges) mV/g with 15 Vdc excitation FREQUENCY RESPONSE 1 to 100 Hz for 7596A-2, 20 to 10000 Hz for all other ranges ZERO MEASURAND OUTPUT mV MAXIMUM TRANSVERSE SENSITIVITY % of sensitivity ACCESSORIES (included) EHW265 (2) SIZE 4, FLAT WASHERS EH409 (2) 4-40 X 3/8 INCH CAP SCREWS EHM464 (1) HEX WRENCH OPTIONAL ACCESSORIES 24328 4 CONDUCTOR SHIELDED CABLE 7990 TRIAXIAL MOUNTING BLOCK NOTES 1. Reference frequency is 20 Hz on the 2 g range. 2. Over the excitation range 8.5 to 30 Vdc. Sensitivity changes +0.1%/V typical and zero measurand output changes -0.5 mV/V typical. 3. Full scale output (FSO) is nominally 4 volts. 4. 1% is typical. 1% maximum available on special order. 5. THRESHOLD = MAX. RESIDUAL NOISE; 0.5 TO 100 Hz SENSITIVITY 6. Per ISA 37.2 at 250 Microstrain. 7. At 100 Gauss, 60 Hz. 8. Current drain increases slightly with increasing excitation; typical change is +.06 mA per volt from 8.5 to 30 Vdc. 9. Maintain high levels of precision and accuracy using Endevco's factory calibration services. Call Endevco’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 Endevco reserve the right to modify these specifications without notice. Endevco 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 Endevco synonymous with reliability. ENDEVCO CORPORATION, 30700 RANCHO VIEJO ROAD, SAN JUAN CAPISTRANO, CA 92675 USA (800) 982-6732 (949) 493-8181 fax (949) 661-7231 www.endevco.com Email:[email protected] 0603 REV C