PCB Test & Measurement Seite 165

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For Additional Specification Information Visit www pcb com PCB PIEZOTRONICS INC 716 684 0001 Fax 716 685 3886 163 Technical Information Strain General Installation Refer to the Installation Drawing for specific outline dimensions and installation details for your particular model It is important that the mounting surface is clean and free of paint oil or other coatings that could prevent the proper transfer of strain into the mounting pads of the sensor Poor surface contact may affect sensor sensitivity and result in erroneous data Prior to mounting it is recommended that the machine surface and the mounting pads of the sensor be cleaned with acetone This will maintain proper coupling with these mating surfaces and prevent slippage at peak strain Connect one end of the coaxial cable to the sensor connector and the other end to the XDCR jack on the signal conditioner Make sure to tighten the cable connector to the sensor DO NOT spin the sensor onto the cable as this fatigues the cable s center pin resulting in a shorted signal and a damaged cable If the cable cannot be attached prior to sensor installation the protective cap should remain on the connector to prevent contamination or damage For installation in dirty humid or rugged environments it is suggested that the connection be shielded against dust or moisture with shrink tubing or other protective material Strain relieving the cable sensor connection can also prolong cable life Mounting cables to a test structure with tape clamps or adhesives minimizes the chance of damage Strain Sensor Installation Figure 46 displays the sensor mounted using the supplied mounting screw to a minimum torque of 10 N m Allow for the static component of the signal to discharge prior to calibration Installations not preloaded to the recommended value or that utilizes a screw of different material and or dimensions than the supplied screw may yield inaccurate output readings The supplied screw allows proper strain transmission to the sensor while holding the sensor in place Properly machined holes for the mounting screw will ensure proper vertical orientation of the sensor Refer to the installation drawing for additional mounting details Consult a PCB applications engineer for calibration and output recommendations Polarity Extension of the mounting area of an ICP strain sensor produces a positive going voltage output The retraction of the mounting area produces a negative going voltage output Low Frequency Monitoring Strain sensors used for applications in short term steady state monitoring such as sensor calibration or short term quasistatic testing should be powered by signal conditioners that operate in DC coupled mode PCB Series 484 Signal Conditioner operates in either AC or DC coupled mode and may be supplied with gain features or a zero clamped output often necessary in repetitive positive polarity pulse train applications If you wish to learn more about ICP sensors consult PCB s General Signal Conditioning Guide a brochure outlining the technical specifics associated with piezoelectric sensors This brochure is available from PCB by request free of charge Calibration Strain sensors are calibrated relative to a strain gage reference sensor A calibration certificate is supplied with each strain sensor providing its relative voltage sensitivity mV µε A calibration must be performed once strain sensors are installed in the specific equipment being measured This is necessary so that a direct comparison of relative data can be made thereby allowing the user to set control limits and properly monitor a specific event as well as the entire process Series M240 Industrial ICP Strain Sensors Figure 46 Strain Sensor Installation 1 14 29 0 0 60 15 2 1 58 40 1 0 23 5 8 0 18 4 6 0 67 17 0 10 32 Connector M6 Mounting Screw supplied Dimensions in inches mm 9 T Mcatalog 2011 Seite 125 166 SYN G500 21 04 11 18 04 Seite 169


Vorschau PCB Test & Measurement Seite 165