1005939-1.

MiniSense 100 Vibration Sensor High Sensitivity Good Frequency Response Excellent Linearity Shielded Construction Analog Output Withstands High Shock The Minisense 100 is a low-cost cantilever-type vibration sensor loaded by a mass to offer high sensitivity at low frequencies. The pins are designed for easy installation and are solderable. Horizontal and vertical mounting options are offered as well as a reduced height version. 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. Dimensions (in millimeters) The mass may be modified to obtain alternative frequency response and sensitivity selection (consult factory). APPLICATIONS       Washing Machine Load Imbalance Vehicle Motion Sensor Anti-Theft Devices Vital Signs Monitoring Tamper Detection Impact Sensing FEATURES         High Voltage Sensitivity (1 V/g) Over 5 V/g at Resonance Horizontal or Vertical Mounting Shielded Construction Solderable Pins, PCB Mounting Low Cost < 1% Linearity Up to 40 Hz (2,400 rpm) Operation Below Resonance MiniSense 100 Vibration Sensor Rev 1 www.meas-spec.com 1 of 4 05/12/2009 MiniSense 100 Vibration Sensor performance specifications Typical properties/specifications Typical Properties (at 25 °C) Parameter Voltage Sensitivity (open-circuit, baseline) Charge Sensitivity (baseline) Resonance Frequency Voltage Sensitivity (open-circuit, at resonance) Upper Limiting Frequency (+3 dB) Linearity Capacitance Dissipation Factor Inertial Mass Value 1.1 260 75 6 Units V/g pC/g Hz V/g 42 +/-1 244 0.018 0.3 Hz % pF (none) gram Environmental Specifications Storage Temperature Operating Temperature Weight MiniSense 100 Vibration Sensor Rev 1 -40 to +80 deg C -20 to +60 deg C Minisense 100H 0.5 gram Minisense 100V 0.6 gram www.meas-spec.com 2 of 4 05/12/2009 MiniSense 100 Vibration Sensor functional description The MiniSense 100 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 mass at the tip 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 quoted above. The sensitivity at resonance is significantly higher. Impacts containing high-frequency components will excite the resonance frequency, as shown in the plot above (response of the MiniSense 100 to a single half-sine impulse at 100 Hz, of amplitude 0.9 g). The ability of the sensor to detect low frequency motion is strongly influenced by the external electrical circuit, as described below (see “Electrical Description”). electrical description The MiniSense 100 behaves electrically as an “active” capacitor: it may be modelled 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/(2πRC). The impedance of the sensor is approximately 650 M ohm 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. External R (Ω) 10 M 100 M 1G Lower Limiting Frequency (-3 dB roll-off) LLF (Hz) Desired LLF (Hz) Required R (Ω) 65 10 65 M 6.5 1 650 M 0.65 0.1 6.5 G Electrical Impedance Low frequency roll-off 10 Magnitude (dB) Impedance (ohms) 1E+10 1E+09 1E+08 1E+07 1E+06 0.1 MiniSense 100 Vibration Sensor Rev 1 1 10 Frequency (Hz) 100 0 -10 1G -20 100 M -30 -40 0.1 www.meas-spec.com 3 of 4 1 Frequency (Hz) 10 05/12/2009 MiniSense 100 Vibration Sensor off-axis sensitivity The sensitivity of the Minisense 100 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. Sensitivity (dB re nominal) Off-axis Response 0 -10 axial -20 theory -30 vertical -40 -50 0 30 60 90 120 Rotation angle (deg) 150 180 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 rights 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. ordering information Description Horizontal Mounting Vertical Mounting Horizontal Mounting Reduced Height Model No. LDTC-H LDTC-V LDTC-RH Part No. 1005939-1 1005940-1 1006015-1 North America Europe Asia Measurement Specialties, Inc. 1000 Lucas Way Hampton, VA 23666 Sales and Customer Service Tel: +1-800-745-8008 or +1-757-766-1500 Fax: +1-757-766-4297 Technical Support Email: piezo@meas-spec.com MEAS Deutschland GmbH Hauert 13 44227 Dortmund Germany Sales and Customer Service Tel: +49 (0)231 9740 21 Technical Support Tel: +49 (0)6074 862822 Email: piezoeurope@meas-spec.com Measurement Specialties (China), Ltd. No. 26 Langshan Road Shenzhen High-Tech Park (North) Nanshan District Shenzhen, China 518107 Sales and Customer Service Tel: +86 755 3330 5088 Technical Support Email: piezo@meas-spec.com MiniSense 100 Vibration Sensor Rev 1 www.meas-spec.com 4 of 4 05/12/2009