MiniSense 100NM Vibration Sensor High sensitivity Higher resonant frequency Solderable Shielded Rugged Withstands high shock DESCRIPTION The MiniSense 100NM is a low-cost cantilever-type vibration sensor offering moderate sensitivity over a useful frequency band up to 200 Hz. Pins are designed for easy installation and are solderable. The active sensor area is shielded for improved RFI/EMI rejection. Rugged, flexible PVDF sensing element withstands high shock overload. Sensor has excellent linearity and dynamic range, and may be used for detecting either continuous vibration or impacts. The MiniSense 100NM acts as a cantilever-beam accelerometer. When the beam is mounted horizontally, acceleration in the vertical plane creates bending in the beam, due to the inertia of the beam. Strain in the beam creates a piezoelectric response, which may be detected as a charge or voltage output across the electrodes of the sensor. The sensor may be used to detect either continuous or impulsive vibration or impacts. For excitation frequencies below the resonant frequency of the sensor, the device produces a linear output governed by the baseline sensitivity. The sensitivity at resonance is significantly higher. Impacts containing high-frequency components will excite the resonance frequency. The ability of the sensor to detect low frequency motion is strongly influenced by the external electrical circuit. FEATURES High voltage sensitivity (65 mV/g) Over 6 mV/g at resonance Horizontal or vertical mounting Shielded construction Solderable pins, PCB mounting Low cost 1% linearity Up to 200 Hz (12,000 rpm) operation below resonance MiniSense 100NM APPLICATIONS Low cost vibration sensing Car alarms Body movement Medical applications Security systems www.meas-spec.com 1/4 8/1/2011 MiniSense 100NM Vibration Sensor PERFORMANCE SPECIFICATIONS Parameter Voltage Sensitivity (open-circuit, baseline) Typical Value, at T A = 25 C 65 Units mV/g Charge Sensitivity (baseline) 16 pC/g Resonance Frequency 360 Hz Voltage Sensitivity (open-circuit, at resonance) 625 mV/g Upper Limiting Frequency (+3 dB) 200 Hz Linearity +/-1 % Capacitance 245 pF 0.018 (none) Storage Temperature -40 to 80 C Operating Temperature -20 to 60 0.2 C Dissipation Factor Environmental Specifications Weight grams MECHANICAL DIMENSIONS in mm Above: Top view Below: Side view MiniSense 100NM Description Part Number Minisense 100 No Mass 1007158-1 www.meas-spec.com 2/4 8/1/2011 MiniSense 100NM Vibration Sensor PERFORMANCE CURVES M100NM VOLTAGE SENSITIVITY Electrical Description The MiniSense 100NM behaves electrically as an active capacitor; it may be modeled as a perfect voltage source (voltage proportional to applied acceleration) in series with the quoted device capacitance. Any external input or load resistance will form a high-pass filter, with a roll-off frequency as tabulated above, or calculated from the formula f(c) = 1/(2RC). The impedance of the sensor is approximately 650 M at 1 Hz. The active sensor element is electrically shielded, although care should be taken in the PCB design to keep unshielded traces as short as possible. Lower Limiting Frequency (-3 dB roll-off) External R () LLF (Hz) Desired LLF (Hz) Required R () 10 M 65 10 65 M 100 M 6.5 1 650 M 1G 0.65 0.1 6.5 G ELECTRICAL IMPEDANCE LOW FREQUENCY ROLL-OFF 1G 100 M MiniSense 100NM www.meas-spec.com 3/4 8/1/2011 MiniSense 100NM Vibration Sensor PERFORMANCE CURVES (CONT) On-Axis Sensitivity The sensitivity of the Minisense 100NM follows a cosine law, when rotated horizontally around its axis, or vertically around its mid-point. At 90 degrees rotation in either plane, both baseline sensitivity and sensitivity at resonance are at a minimum. In theory, sensitivity should be zero in this condition. It is likely that some sensitivity around the resonance frequency will still be observed - but this may be unpredictable and is likely to be at least -16 dB with reference to the on-axis response. Note that the sensitivity at 30 degrees rotation is -1.25 dB (87% of on-axis response), at 60 degrees, it falls to -6 dB (50%). The plots below show the change in sensitivity observed for either: 1) Rotation about major axis of sensing element, or 2) Rotation about mid-point of sensing element. OFF-AXIS RESPONSE TECHNICAL CONTACT INFORMATION North America Europe Asia Measurement Specialties, Inc. 1000 Lucas Way Hampton, VA 23666 Tel: 1-800-745-8008 Fax: 1-757-766-4297 Sales: piezo@meas-spec.com MEAS Deutschland GmbH Hauert 13 44227 Dortmund Germany Sales & Customer Service: +49 (0)231 9740 21 Technical Support: +44 (0)138 38700 01 Email: piezoeurope@meas-spec.com Measurement Specialties (China) Ltd. No. 26 Langshan Road, Shenzhen High-Tech Park (North) Nanshan District, Shenzhen 518057 Tel: +86 755 3330 5088 Email: sales.china@meas-spec.com The information in this sheet has been carefully reviewed and is believed to be accurate; however, no responsibility is assumed for inaccuracies. Furthermore, this information does not convey to the purchaser of such devices any license under the patent rig hts to the manufacturer. Measurement Specialties, Inc. reserves the right to make changes without further notice to any product herein. Measurement Specialties, Inc. makes no warranty, representation or guarantee regarding the suitability of its product for any particular purpose, nor does Measurement Specialties, Inc. assume any liability arising out of the application or use of any product or circuit and specifically disclaims any and all liability, including without limitation consequential or incidental damages. Typical parameters can and do vary in different applications. All operating parameters must be validated for each customer application by customer's technical experts. Measurement Specialties, Inc. does not convey any license under its patent rights nor the rights of others. MiniSense 100NM www.meas-spec.com 4/4 8/1/2011