Model 3022 � Vibration/Shock Monitoring PC Board Mountable Accelerometer � Modal Analysis � Motion Control Millivolt Output � Crash Testing Low Cost � 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 � Adhesive Mount bolt the sensor to a mounting location, see the Model 3028. Please refer to the Models 3052 and 3058 for accelerometers � ±0.5% Non-linearity (typical) with integral temperature compensation. � ±1.0% Temperature Performance (with comp resistors—typical) � DC Response � Built-in Damping � Built-in Overrange Stops � Low Power � Pins or No Pins STANDARD RANGES Range g Range g ±2 ±50 ● ● ±5 ±100 ● ● ±10 ±200 ● ● ±20 ±500 ● ● 2-12 Accelerometer – Unamplified PC Board Mountable Accelerometer Model 3022 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  Rstc sets the excitation voltage ramp to compensate the sensitivity CR1: 1N914 or equivalent error due to temperature. Op Amps: LT1014, LM324 or equivalent  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.  Rs calibrates the output span.  Vcc must be >8 VDC. April 2000 Accelerometer – Unamplified 2-13 Model 3022 PC Board Mountable Accelerometer PERFORMANCE SPECIFICATIONS Supply Voltage: 5.0 VDC Ambient Temperature: 25°C (Unless otherwise specified) RANGE PARAMETERS ±2G ±5G ±10G ±20G UNITS NOTES Frequency Response [MIN] 0-250 0-300 0-400 0-600 Hz 1, 9 Mounted Resonant Frequency [MIN] 700 800 1000 1500 Hz 8, 9 Sensitivity (MIN/MAX) 8.0/20.0 6.0/15.0 3.0/6.0 1.5/3.0 mV/g 2 RANGE PARAMETERS ±50G ±100G ±200G ±500G UNITS NOTES Frequency Response [MIN] 0-1000 0-1500 0-2000 0-2400 Hz 1, 9 Mounted Resonant Frequency [MIN] 2000 3000 4000 5000 Hz 8, 9 Sensitivity (MIN/MAX) 0.6/1.5 0.3/0.6 0.15/0.3 0.06/0.15 mV/g 2 PARAMETERS MIN TYP MAX UNITS NOTES Zero Acceleration Output 5.0 25.0 ±mV 9 Damping Ratio 0.4 0.7 0.9 8, 9 Non-linearity 0.5 1.0 ±% Span 4 Transverse Sensitivity 1.0 3.0 ±% Span Input & Output Resistance 2.5 3.5 6.5 kΩ 9 Temperature Error - Span 1.0 2.0 ±% Span 3, 5 Temperature Error - Zero 1.0 2.0 ±% Span 3, 5 Supply Voltage 5.0 10.0 VDC Output Noise 1.0 µV p-p 6 Output Load Resistance 5 MΩ Acceleration Limits (Any Direction) 20X Rated 7 Operating Temperature -40°C to +125°C Storage Temperature -55°C to +150°C Weight (with pins) 6.5 Grams Materials Alumina ceramic substrate with alumina ceramic cap Notes 1. The frequency response is defined as the range of frequencies over 5. Compensated temperature range: 0-50°C in reference to 25°C. which the device sensitivity is within ±5% of the DC value. 6. 10 Hz to 1 kHz. 2. Output voltage increases for positive acceleration; output voltage 7. 400g for ±2g, ±5g, and ±10g versions. 20X or 2000g for other decreases for negative acceleration. versions, whichever is less. 3. Percentage values are with external compensation. The uncompensated 8. For sensors having a resonant frequency greater than 5 kHz, the temperature coefficients are measured and specified with each unit. In calibration data sheet will indicate ">5 kHz." In addition, the damping addition, the values of the resistors that provide a temperature ratio will indicate N/A. compensated output are provided with each unit. These resistors are 9. Actual test data for this parameter is included on the calibration sheet for use in the circuit shown in Figure 2. provided with each sensor. A sample of this calibration sheet is shown 4. Best Fit Straight Line. For full scale ranges of 10g or less, the maximum as Figure 1. non-linearity is ±2%. 2-14 Accelerometer – Unamplified PC Board Mountable Accelerometer Model 3022 DIMENSIONS CONNECTIONS LTR 2 - 10 g 20 - 500 g 0.300 ± 0.005 0.265 ± 0.005 “A” DIM [7.62 ± 0.13] [6.73 ± 0.13] 0.250 ± 0.005 0.240 ± 0.005 “B” DIM [6.35 ± 0.13] [6.10 ± 0.13] 0.032 ± 0.004 0.032 ± 0.004 “C” DIM [0.81 ± 0.10] [0.81 ± 0.10] ORDERING INFORMATION April 2000 Feel free to contact customer service with any questions at Accelerometer – Unamplified 2-15 Toll free 1(800)745-8008; Phone (757)766-1500; Fax (757)766-4297