Model 3022 þ Vibration/Shock Monitoring PC Board Mountable Accelerometer þ Modal Analysis Millivolt Output þ Motion Control Low Cost þ Crash Testing þ Aerospace DESCRIPTION The Model 3022 is a piezoresistive silicon accelerometer. It is packaged on a ceramic substrate with an epoxy sealed ceramic cover and is designed for adhesive mounting. A detailed calibration sheet provides test data and resistor compensation values for each sensor. The accelerometer consists of a micro machined silicon mass suspended by multiple beams from a silicon frame. Piezoresistors located in the beams change their resistance as the motion of the suspended mass changes the strain in the beams. Silicon caps on the top and bottom of the device are added to provide over-range stops. This design provides for a very low profile, high shock resistance, durability and built-in damping over a wide usable bandwidth. Each sensor is individually serialized. FEATURES For an accelerometer with a mounting bracket designed to þ Adhesive Mount bolt the sensor to a mounting location, see the Model 3028. þ ±0.5% Non-linearity (typical) Please refer to the Models 3052 and 3058 for accelerometers þ ±1.0% Temperature Performance (with comp resistors—typical) þ DC Response þ Built-in Damping þ Built-in Overrange Stops þ Low Power þ Pins or No Pins with integral temperature compensation. STANDARD RANGES 2-12 Range g Range g ±2 ● ±50 ● ±5 ● ±100 ● ±10 ● ±200 ● ±20 ● ±500 ● Accelerometer – Unamplified Model 3022 PC Board Mountable Accelerometer CALIBRATION DATA Figure 1. Calibration Data Sheet A calibration data sheet similar to the sample shown above is to the test data, the values of calibration and temperature included with each unit. The calibration sheet provides the compensation resistors are also included. measured test and calibration data for the sensor. In addition SIGNAL CONDITIONING Figure 2. Typical Temperature Compensation and Amplification Circuit (component values specified for each sensor) Q1: 2N3904 • CR1: 1N914 or equivalent Op Amps: LT1014, LM324 or equivalent Rstc sets the excitation voltage ramp to compensate the sensitivity error due to temperature. • Rset sets the excitation voltage to 5V at 25°C. • Rzb1, Rzb2 and Rztc1 and Rztc2 calibrate the zero offset and compensate the offset error due to temperature. Accelerometer – Unamplified • Rs calibrates the output span. • Vcc must be >8 VDC. April 2000 2-13 Model 3022 PC Board Mountable Accelerometer PERFORMANCE SPECIFICATIONS Supply Voltage: 5.0 VDC Ambient Temperature: 25°C (Unless otherwise specified) RANGE PARAMETERS Frequency Response [MIN] Mounted Resonant Frequency [MIN] Sensitivity (MIN/MAX) ±2G ±5G ±10G ±20G UNITS 0-250 0-300 0-400 0-600 Hz NOTES 1, 9 700 800 1000 1500 Hz 8, 9 8.0/20.0 6.0/15.0 3.0/6.0 1.5/3.0 mV/g 2 NOTES RANGE PARAMETERS Frequency Response [MIN] Mounted Resonant Frequency [MIN] Sensitivity (MIN/MAX) PARAMETERS ±50G ±100G ±200G ±500G UNITS 0-1000 0-1500 0-2000 0-2400 Hz 1, 9 2000 3000 4000 5000 Hz 8, 9 0.6/1.5 0.3/0.6 0.15/0.3 0.06/0.15 mV/g 2 NOTES MIN TYP MAX UNITS 5.0 25.0 ±mV 0.7 0.9 Non-linearity 0.5 1.0 ±% Span Transverse Sensitivity 1.0 3.0 ±% Span 3.5 6.5 kΩ 9 1.0 2.0 ±% Span 3, 5 3, 5 Zero Acceleration Output Damping Ratio Input & Output Resistance 0.4 2.5 Temperature Error - Span Temperature Error - Zero 1.0 2.0 ±% Span Supply Voltage 5.0 10.0 VDC Output Noise Output Load Resistance 1.0 µV p-p 5 Acceleration Limits (Any Direction) -40°C to +125°C Storage Temperature -55°C to +150°C 4 6 MΩ 20X Operating Temperature 9 8, 9 Rated Weight (with pins) 6.5 Grams Materials Alumina ceramic substrate with alumina ceramic cap 7 Notes 1. The frequency response is defined as the range of frequencies over which the device sensitivity is within ±5% of the DC value. 5. 6. 10 Hz to 1 kHz. 2. Output voltage increases for positive acceleration; output voltage decreases for negative acceleration. 7. 400g for ±2g, ±5g, and ±10g versions. 20X or 2000g for other versions, whichever is less. 3. Percentage values are with external compensation. The uncompensated temperature coefficients are measured and specified with each unit. In addition, the values of the resistors that provide a temperature compensated output are provided with each unit. These resistors are for use in the circuit shown in Figure 2. 8. For sensors having a resonant frequency greater than 5 kHz, the calibration data sheet will indicate ">5 kHz." In addition, the damping ratio will indicate N/A. 9. Actual test data for this parameter is included on the calibration sheet provided with each sensor. A sample of this calibration sheet is shown as Figure 1. 4. Best Fit Straight Line. For full scale ranges of 10g or less, the maximum non-linearity is ±2%. 2-14 Compensated temperature range: 0-50°C in reference to 25°C. Accelerometer – Unamplified Model 3022 PC Board Mountable Accelerometer LTR 2 - 10 g 20 - 500 g “A” DIM 0.300 ± 0.005 [7.62 ± 0.13] 0.265 ± 0.005 [6.73 ± 0.13] “B” DIM 0.250 ± 0.005 [6.35 ± 0.13] 0.240 ± 0.005 [6.10 ± 0.13] “C” DIM 0.032 ± 0.004 [0.81 ± 0.10] 0.032 ± 0.004 [0.81 ± 0.10] CONNECTIONS ORDERING INFORMATION April 2000 Accelerometer – Unamplified 2-15