SILICON DESIGNS, INC Model 2440 TRIAXIAL ANALOG ACCELEROMETER MODULE ! 3 Axis Acceleration Sensing ! Capacitive Micromachined ! Nitrogen Damped ! Low Noise ! ±5V Single Ended Outputs ! Fully Calibrated ! Low Power Consumption ! -55 to +125E EC Operation ! ±11 to ±16 VDC Power ! 6 Wire Connection ! Serialized for Traceability ! Responds to DC & AC Acceleration ! Outputs Referenced to External Ground ! Non Standard g Ranges Available ! Rugged Black Anodized Aluminum Module ORDERING INFORMATION Full Scale Model Acceleration Number ± 2g ± 5g ± 10 g ± 25 g ± 50 g ±100 g ±200 g DESCRIPTION 2440-002 2440-005 2440-010 2440-025 2440-050 2440-100 2440-200 The Model 2440 triaxial accelerometer is a higher performance and wider temperature range version of the model 2430. It combines three orthogonally mounted Model 1221L accelerometers, in a rugged case for measuring accelerations in commercial and industrial environments. This low noise module is tailored for zero to medium frequency instrumentation applications. The anodized aluminum case is epoxy sealed and is easily mounted via two #8 (or M4) screws. The design includes an instrumentation amplifier on each axis providing high drive capability and low output impedance. On-board voltage regulation and an internal voltage reference eliminate the need for precision power supplies. No power supply current flows through the OUTPUT REF wire; this high impedance input is used only as a reference for the acceleration outputs which reduces cross talk among the three channels by rejecting noise from voltage differences between the user's data acquisition equipment and power supply grounds. The 2440 is relatively insensitive to temperature changes and gradients. An initial calibration sheet (2440-CAL) is included and periodic calibration checking is available. OPERATION The Model 2440 produces three analog voltage outputs which vary with acceleration. The Z axis is perpendicular to the bottom of the package, with positive acceleration defined as a force pushing on the bottom of the package. The X and Y axis directions are marked on the cover with positive acceleration defined as acceleration in the direction of the axis arrow. The outputs are single ended and vary with respect to the voltage at the OUTPUT REF input which should be approximately centered between the +VS and -VS supply voltages. The output scale factor is independent of the supply voltages from ±12 to ±16 volts. At zero acceleration, the output voltage is nominally zero volts; at ±full scale acceleration the output voltage is ±5 volts respectively. APPLICATIONS VIBRATION MONITORING VIBRATION ANALYSIS CRASH TESTING ROBOTICS MACHINE CONTROL INSTRUMENTATION MODAL ANALYSIS ROTATING MACHINERY MONITOR Silicon Designs, Inc. ! 1445-NW Mall Street, Issaquah, WA 98027-5344 ! Phone: 425-391-8329 ! Fax: 425-391-0446 web site: www.silicondesigns.com [page 1] Sep 07 Model 2440 Triaxial Analog Accelerometer Module SIGNAL DESCRIPTIONS +VS (Power): Reddish brown wire. Apply +11 to +16 Volts DC with respect to OUTPUT REF. -VS (Power): Black wire. Apply -11 to -16 Volts DC with respect to OUTPUT REF. OUTPUT REF (Input): White wire. The X, Y & Z outputs are referenced to this potential. This input is usually tied to a potential halfway between the +VS and -VS voltages. This input may also be used to offset the output but the voltage difference between this input and either supply voltage (+VS or -VS) must be greater than or equal to 11V. X, Y & Z (Outputs): Green, Light Brown & Light Blue wires respectively. These output voltages are proportional to acceleration; they increase with positive acceleration and decrease with negative acceleration. At zero acceleration the output is nominally equal to zero volts with respect to OUTPUT REF. PERFORMANCE - By Model: VS=±12 to ±16VDC, TC=25EC. MODEL NUMBER UNITS 2440-002 2440-005 2440-010 2440-025 2440-050 2440-100 2440-200 Input Range Frequency Response (Nominal, 3 dB) 1 Sensitivity Output Noise (RMS, typical) ±2 0 - 400 ±5 0 - 600 ±10 0 - 1000 ±25 0 - 1500 ±50 0 - 2000 ±100 0 - 2500 ±200 0 - 2500 g Hz 2500 12 1000 14 500 15 200 38 100 75 50 150 25 300 mV/g 2000 Max. Mechanical Shock (0.1 ms) Note 1: 250Hz ±100Hz, -3dB bandwidth, optionally available. µg/(root Hz) g PERFORMANCE - All Models: Unless otherwise specified VS=±12 to ±16VDC, TC=25EC. PARAMETER MIN Cross Axis Sensitivity -002 -005 thru -200 -002 -005 thru -200 Bias Calibration Error Bias Temperature Shift (TC= -40 to +80EC) Non-Linearity (-90 to +90% of Full Scale) 2, 4 -002 thru -010 -250 -025 thru -200 -150 -002 thru -050 -100 -200 MAX UNITS 2 3 4.0 1.5 200 100 2 % 100 50 1 2 Scale Factor Calibration Error Scale Factor Temperature Shift (TC= -40 to +80EC) TYP 0.15 0.25 0.40 >65 1 % of span (ppm of span)/EC % +150 ppm/EC 0.5 1.0 1.5 % of span Power Supply Rejection Ratio 50 dB Output Impedance Ohm Operating Voltage (VS) ±11 3 ±16 V Operating Current (X, Y & Z outputs open) 30 40 mA Mass (not including cable) 30 grams Cable Mass 15 grams/meter Note 2: 100g versions and above are tested from -65g to +65g. Note 4: Tighter tolerances available upon request. Note 3. Operation with VS below ±12V may result in some performance degradation. SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE Silicon Designs, Inc. ! 1445-NW Mall Street, Issaquah, WA 98027-5344 ! Phone: 425-391-8329 ! Fax: 425-391-0446 web site: www.silicondesigns.com [page 2] Sep 07 Model 2440 Triaxial Analog Accelerometer Module CABLE SPECIFICATIONS & LENGTH CONSIDERATIONS The cable consists of six 28 AWG (7x36) tin plated copper wires with FEP insulation. The cable jacket is an FEP tape wrap with a nominal outer diameter of 0.125”. Cable lengths of up to 15 meters (50 feet) can be added to the model 2440's standard 1 meter cable without the need to test for output instability. For lengths longer than 15 meters we recommend you check each individual installation for oscillation by tapping the accelerometer and watching the differential output for oscillation in the 20kHz to 50kHz region. If no oscillation is present then the cable length being used is OK. From the standpoint of output current drive and slew rate limitations, the model 2440 is capable of driving over 600 meters (2000 feet) of its cable type but at some length between 15 and 600 meters, each device will likely begin to exhibit oscillation. SENSOR LOCATIONS SINGLE SUPPLY OPERATION The model 2440 can be powered using a single +20 to +32V supply but two additional resistors are needed and you must make the following connections. Connect the -VS wire to your power supply’s ground. Connect the +VS wire to the positive output of your power supply VP. Connect one resistor (RUPPER) between your supply voltage and the OUTPUT REF wire. Connect another resistor (RLOWER) between ground and the OUTPUT REF wire. The two resistors form a resistive divider which creates a +5V source for OUTPUT REF. This +5V reference needs to have a source impedance of about 1000Ω so use the following equations to calculate values for the resistors depending upon your supply voltage VP. R LOWER = V P − 5 RUPPER = R LOWER 5 1000 ⋅ V P VP − 5 For this mode of operation, the voltage swing of the three outputs is limited to 8V (+1 to +9V) so the g-range over which each model will operate is reduced according to the table below. MODEL NUMBER Input Range (single supply mode) Sensitivity (single supply mode) Output Range (single supply mode) 2440x-002 2440x-005 2440x-010 2440x-025 2440x-050 2440x-100 2440x-200 ± 1.6 2500 ±4 1000 ±8 500 ± 20 ± 40 200 100 8V (+1 to +9V) ± 80 50 ± 160 25 UNITS g mV/g Volts A custom version of the model 2440 that can operate with a single supply as low as 12V can be special ordered but a custom order charge may apply for quantities less than 10. SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE Silicon Designs, Inc. ! 1445-NW Mall Street, Issaquah, WA 98027-5344 ! Phone: 425-391-8329 ! Fax: 425-391-0446 web site: www.silicondesigns.com [page 3] Sep 07