Piezoelectric Accelerometer
`
`ENDEVCO
`MODEL
`23
`
`
`
`SER NO.XXXX
`
`Z
`
`X
`
`Y
`
`Actual size
`
`6.00
`(152.4)
`
`.300
`(7.62)
`
`IDENTIFICATION LABEL
`
`.020/.014 (.51/.36) DIA.
`ENDEVCO 3003A CABLE ASSEMBLY
`(REPLACEABLE)
`
`# 1-64 UNC-2B THD. MATES WITH
`ENDEVCO 3095A CABLE
`
`X
`
`Y
`
`Z
`
`.006 TYPICAL
`(.15)
`
`.250
`(6.35)
`
`.200
`(5.08)
`
`.008 (.20)
`.006 (.15)
`
`MOUNTING SURFACE
`
`.220 DIA
`(5.59)
`
`STANDARD TOLERANCCE
` INCHES (MILLIMETERS)
`.XX = +/- .02 (.X = +/- .5)
`.XXX = +/- .010 (.XX = +/- .25)
`
`TYPICAL TEMPERATURE RESPONSE
`
`TYPICAL CAPACITANCE
`
`CHARGE SENSITIVITY
`
`30
`
`20
`
`10
`
`0
`
`-10
`
`-20
`
`-100
`
`0
`
`100
`
`200
`
`300
`
` (-73) (-18) (38) (93) (149)
`TEMPERATURE oF ( oC)
`
`Model 23
`• Requires No External Power
`• Radial Shear
`• World’s Smallest Triaxial
`• Light Weight (0.85 gm)
`• Ground Isolated
`• Adhesive Mounting
`
`DESCRIPTION
`The ENDEVCO® Model 23 is the world's
`smallest triaxial piezoelectric accelerometer,
`designed specifically for vibration measurement
`in three orthogonal axes on small objects such
`as scaled models, circuit boards, and disk drives.
`Its light weight, 0.85 gm without the replace-
`able low-noise cables, effectively eliminates mass
`loading effects. All three low-noise cables exit
`from a single surface to allow mounting flexibil-
`ity. The accelerometer is a self-generating device
`that requires no external power source for
`operation.
`
`The Model 23 features ENDEVCO’s
`PIEZITE® Type P-8 crystal elements, operating
`in radial shear mode, which exhibits excellent
`output sensitivity stability over time. Signal
`ground is isolated from the mounting surface of
`the unit by a hard anodized surfaces. Specially
`designed low-noise coaxial cables are supplied
`for error-free operation. A unit/cable removal
`tool is included in the package to ensure proper
`removal in the field.
`
`ENDEVCO Signal Conditioner Models 133,
`2775A or CCAS™ are recommended for use
`with this high impedance accelerometer.
`
`% DEVIATION
`
`20
`
`15
`
`051
`
`0
`
`-5
`
`-10
`
`-15
`
`-20
`100000
`
`TYPICAL AMPLITUDE RESPONSE
`
`X & Y Axis
`
`Z Axis
`
`1
`
`10
`
`1000
`100
`FREQUENCY IN HERTZ
`
`10000
`
`FITBIT, INC. v. LOGANTREE LP
`Ex. 1018 / Page 1 of 2
`
`

`
`Piezoelectric Accelerometer
`
`SPECIFICATIONS
`The following performance specifications conform to ISA-RP-37.2 (1964) and are typical values, referenced at +75°F (+24°C) and 100 Hz,
`unless otherwise noted. Calibration data, traceable to National Institute of Standards and Technology (NIST), is supplied.
`
`ENDEVCO
`MODEL
`23
`
`DYNAMIC CHARACTERISTICS
`CHARGE SENSITIVITY
`TYPICAL
`MINIMUM
`FREQUENCY RESPONSE
`RESONANCE FREQUENCY
`AMPLITUDE RESPONSE [1]
`Z Axis: ±5%
`X & Y Axis: + 10%, -5%
`TEMPERATURE RESPONSE
`TRANSVERSE SENSITIVITY
`AMPLITUDE LINEARITY [3]
`Per 250 g, 0 to 2000 g
`
`ELECTRICAL CHARACTERISTICS
`OUTPUT POLARITY
`
`RESISTANCE
`ISOLATION
`CAPACITANCE
`Including 6 inch Model 3003 Cable Assy
`
`ENVIRONMENTAL CHARACTERISTICS
`TEMPERATURE RANGE
`HUMIDITY
`SINUOSOIDAL VIBRATION LIMIT
`SHOCK LIMIT [2]
`BASE STRAIN SENSITIVITY
`ELECTROMAGNETIC SENSITIVITY
`
`PHYSICAL CHARACTERISTICS
`DIMENSIONS
`WEIGHT
`UNIT ONLY
`UNIT WITH CABLE
`CASE MATERIAL
`CABLE DESCRIPTION [4]
`
`CABLE CAPACITANCE
`MOUNTING [5]
`
`CALIBRATION
`SUPPLIED:
`SENSITIVITY
`Each Axis
`CAPACITANCE
`Including 6 inch replaceable cable
`TRANSVERSE SENSITIVITY
`CHARGE FREQUENCY RESPONSE
`ACCESSORIES
`P/N 18060
`
`ACCELEROMETER AND CABLE
`REMOVAL WRENCH
`Model 3095-120 (10 ft) CABLE ASSEMBLY, Three each
`P/N 16426
`CAPSULE OF SILICONE COMPOUND
`Model 3003A-6 (6 In.)
`CABLE ASSEMBLY, Three each
`
`NOTES
`1. Low-end response of the transducer is a function of its
`associated electronics.
`2. When exposed to high g,and large displacement, the cables
`must be tied down as close to the accelerometer as possible
`to prevent cable whip which will cause cable failure.
`
`Units
`
`pC/g
`pC/g
`
`kHz
`
`Hz
`Hz
`
`%
`%
`
`0.40
`0.30
`See Typical Amplitude Response
`50
`
`1 to 10 000
`1 to 10 000
`See Typical Curve
` 5
`
`1
`
`GW ‡
`GW ‡
`pF
`
`Acceleration applied in the direction of the arrow
`on the unit produces positive output
` 10
` 1
`230
`
`g pk
`g pk
`equiv. g pk/µ strain
`equiv. g rms
`
`-100°F to +300°F (-73°C to +149°C)
`Epoxy sealed, non-hermetic
`1000
`10 000 in any axis
`0.008
`0.09
`
`gm (oz)
`gm (oz)
`
`pC
`
`pC/g
`
`pF
`
`%
`%
`
`See Outline Drawing
`
`0.8 (0.03)
`1.7 (0.06)
`Aluminum Alloy, hard anodized
`Three 0.013 diameter TFE insulated coaxial
`cable, 0.003 diameter CRES center conductor,
`Teflon dialectric. CRES outer sheath
`30
`Adhesive
`
`20 Hz to 10 kHz
`3. 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.
`4. See instruction manual before removing cable assemblies.
`5. Depending on the dynamic and environmental requirements,
`adhesives such as petro-wax, hot-melt glue, and
`cyanoacrylate epoxy (super glue) may be used to mount the
`accelerometer temporarily to the test structure. An adhesive
`mounting kit (P/N 31849) is available as an option from
`Endevco. When removing an epoxy-mounted accelerometer,
`first soften the epoxy with an appropriate solvent, then twist
`the unit off with the supplied removal tool. Failure to heed this
`caution may cause permanent damage to the transducer,
`which is not covered under warranty.
`
`Ex. 1018 / Page 2 of 2
`
`£