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unknown user
07-27-1993, 11:53 PM
MHS: Source date is: 28-Jul-93 09:43 EST

Quite a while ago I solicited information about tri-axial accelerometers for
measuring human accelerations in applications such as heel strike. I have
gathered a summary of companies, information on their lightest accelerometers
and cost. This information may be slightly different from what I have written
down, or it may need completion. I do not endorse or recommend any particular
one. That is up to you depending on your application requirements and budget.
Thank-you for your help. I hope this is useful for your own research.

Regards,

Jon

Jon_Fewster@MCIMail.com

Accelerometers: Company, Model, Features and Costs

General Info: Time Constant = the amount of time for the signal to drop to 63%
of the impulse signal. This constant depends on the mass of the accelerometer.
To detect lower frequencies, larger time constants are required. With many of
these small accelerometers a variation in temperature as small as a breeze may
produce errors.

Develco: (714) 892-7631 FAX (714) 897-1949.
Contact Tim McFadden, VP of Marketing.

Triaxial Piezo-Electric Accelerometer Model A/32

7.5 grams with accelerometers. Approximately 14.5 mm3. A/32 is a mounting
block which holds three A/25/E piezo-electric accelerometers in an orthogonal
arrangement. 3 grams = mounting block, plus 1.5 grams per accelerometer.
Capacitance based: 1.3 pC/g. Resonant frequency, X:30kHz, Y:30kHz, Z:35kHz.

Cost: Triax 2637

Micro-Miniature Triaxial Accelerometer Model A/38

2.3 grams. Contains three A/28/E micro-accelerometers in a set-up similar to
the A/32. Uses a CA/04 Charge Amplifier. 0.25pC/g. Resonant frequency >50kHz.


Cost: Triax 3465

Endevco: (800) 982-6732 or (714) 493-8181 FAX (714) 661-7231
Contact James Mathews.

Model 23, Piezoelectric

1.7grams, 1-2000 Hz. 1% linearity. 0.4 mV/g. Need a charge converter and an
amplifier.

Cost: Triax
Charge converter 1595
Amplifier 1300/channel

7253 A-10 ISOTRON Accelerometer

2.5 grams, 4Hz- . Requires current supplies #2772 (one per channel) or can be
made.

Cost: Triax 1395
Current Source ?

ENTRAN: (800) 635-0650 Contact Bob Levy.

Three EGA-125 Series Accelerometers may be placed in a mounting block (EGA3-
MTG) to achieve triaxial measurement. This system has a mass of 0.7 grams per
sensor plus 10.3 grams for the aluminum mounting block for a total of 12.4
grams. They may have other options.

KISTLER: (716) 691-5100 Contact James Barkowski.

8694M1 PICOTRON

2.5 grams. Crosstalk: 5% of 4mV/g per axis. Frequency responce: 10Hz - 20kHz.
Time constant of 0.5 seconds. Signal conditioning: #5122, gains of 1,10,100.

Cost: Triax 1475
Signal conditioning 695
Cables 95
90
Total $2355

PCB Piezotronics: (716) 684-0001 FAX (716) 684-0987
Contact Ray Limburg, Applications Engineer or Kurt Graulich, Northeast Regional
Manager.
Also may contact Northeast Engineering, Danvers, MA: (508) 774-3010,
FAX (508)777-9008

Miniature Triax Flexural Quartz ICP Accelerometer Model 339A11

0.4" cube. 3.5 grams. 10mV/g, 1 to 5000 Hz (one Hertz is doubtful, 5 is more
realistic), 100 to 1 signal to noise ratio. Accelerometer is an I-beam. No
damping needed.For use with signal conditioner 482A16: switchable gains of 1,
10, 100. Output is analog voltage proportional to applied acceleration:
10mV/g.

Cost:1 Triax, 1950.
4 channel power supply 775.
3 adapters 90
3 coax cables (15') 45
Total: $2860

Additional: Cable 35 + 0.60/ft.
Calibration System 1795