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Model 357M168

 

Charge Output Accelerometer

 

Installation and Operating Manual

 

For assistance with the operation of this product,

contact the PCB Piezotronics, Inc.

 

Toll-free: 716-684-0001

24-hour SensorLine: 716-684-0001

Fax: 716-684-0987

E-mail: [email protected]

Web: www.pcb.com

Summary of Contents for 357M168

Page 1: ...lerometer Installation and Operating Manual For assistance with the operation of this product contact the PCB Piezotronics Inc Toll free 716 684 0001 24 hour SensorLine 716 684 0001 Fax 716 684 0987 E mail info pcb com Web www pcb com ...

Page 2: ...ialized tests including sensitivity at elevated or cryogenic temperatures phase response extended high or low frequency response extended range leak testing hydrostatic pressure testing and others For more information contact your local PCB Piezotronics distributor sales representative or factory customer service representative Returning Equipment If factory repair is required our representatives ...

Page 3: ...ation on particular operating steps The following symbols may be found on the equipment described in this manual This symbol on the unit indicates that high voltage may be present Use standard safety precautions to avoid personal contact with this voltage This symbol on the unit indicates that the user should refer to the operating instructions located in the manual This symbol indicates safety ea...

Page 4: ...E 住房 O O O O O O PCB板 X O O O O O 电气连接器 O O O O O O 压电晶体 X O O O O O 环氧 O O O O O O 铁氟龙 O O O O O O 电子 O O O O O O 厚膜基板 O O X O O O 电线 O O O O O O 电缆 X O O O O O 塑料 O O O O O O 焊接 X O O O O O 铜合金 黄铜 X O O O O O 本表格依据 SJ T 11364 的规定编制 O 表示该有害物质在该部件所有均质材料中的含量均在 GB T 26572 规定的限量要求以下 X 表示该有害物质至少在该部件的某一均质材料中的含量超出 GB T 26572 规定的限量要求 铅是欧洲RoHS指令2011 65 EU附件三和附件四目前由于允许的豁免 CHINA RoHS COMPLIANCE ...

Page 5: ... O Wires O O O O O O Cables X O O O O O Plastic O O O O O O Solder X O O O O O Copper Alloy Brass X O O O O O This table is prepared in accordance with the provisions of SJ T 11364 O Indicates that said hazardous substance contained in all of the homogeneous materials for this part is below the limit requirement of GB T 26572 X Indicates that said hazardous substance contained in at least one of t...

Page 6: ...e with PIEZOELECTRIC CHARGE MODE ACCELEROMETERS SPECIFICATION SHEET INSTALLATION DRAWING AND CALIBRATION INFORMATION ENCLOSED PCB ASSUMES NO RESPONSIBILITY FOR DAMAGE CAUSED TO THIS PRODUCT AS A RESULT OF PROCEDURES THAT ARE INCONSISTENT WITH THIS OPERATING GUIDE ...

Page 7: ...nnector 4 2 5 In Line Differential Charge Amplifier 4 3 INSTALLATION OVERVIEW 4 3 1 Equipment Inspection 4 3 2 Polarity Test 4 3 3 Sensor Location 4 3 4 Mounting Sensor 5 3 5 Route Mineral Insulated Hardline Cable 6 3 5 1 Care 6 3 5 2 Bend Radius 7 3 5 3 Clamp Cable 7 4 POWERING 8 4 1 Installation 8 4 2 Operation 8 5 HIGH TEMPERATURE OPERATION 8 5 1 Introduction 8 5 2 Reduced Resistance at Charge ...

Page 8: ...ere high temperatures preclude the use of accelerometers with built in microelectronics Enclosed is a Specification Sheet which lists the complete performance characteristics of the particular accelerometer 2 CABLING 2 1 General Precautions and Considerations 2 1 1 Proper Cable Type and Care Ascertain that you have ordered the correct cable type Due to the high impedance nature of the output signa...

Page 9: ...Charge Amplifier The differential charge amplifier is purchased separately A conventional method for conditioning the high impedance signal generated by a charge output sensor is to use a differential charge amplifiers operate from an ICP signal conditioner The unit employs a high gain amplifier to perform the impedance transformation The charge output of the transducers may be scaled in terms of ...

Page 10: ...opriate charge amplifier specification sheet for information on low frequency characteristics Figure 1 Assorted Mounting Configurations and Their Effects on High Frequency 3 4 1 STUD MOUNT This mounting technique requires smooth flat contact surfaces for proper operation and is recommended for permanent and or secure installations Stud mounting is also recommended when testing at high frequencies ...

Page 11: ...test object STEP 1 Prepare a smooth flat mounting surface A minimum surface finish of 63 in 0 00016 mm generally works best STEP 2 Stud mount the sensor to the appropriate adhesive mounting base according to the guidelines set forth in STEPS 2 and 3 of the Stud Mount Procedure STEP 3 Place a small portion of adhesive on the underside of the mounting base Firmly press down on the assembly to displa...

Page 12: ...lamp Cable To minimize triboelectric motion induced noise from the cable interfering with the sensors high impedance charge output cable clamps must be used Clamp the cable as close to the transducer as possible and should be attached to the same surface that the head is mounted See Figure 3 taking care not to induce stress into the cable and possibly leading to intermittent or broken connections ...

Page 13: ...ration Once each element is connected allow a few minutes for the system to thermally stabilize Place the switch on the charge amplifier in the OPERATE position and proceed with the measurement It is often convenient to normalize the accelerometer and charge amplifier system to a precise sensitivity such as 10 0 or 100 0 mV g for ease of data analysis This is accomplished with most PCB laboratory ...

Page 14: ...evices As demonstrated in Equation 1 the steady state DC output voltage Eo is Equation 1 i f i o R R e E 1 This equation shows that if the input leakage resistance at the charge amplifier is extremely high approaching infinity the output DC voltage approaches ei usually a very tiny voltage However as Ri decreases the term i f R R 1 increases such that the output voltage can with large ratios of Rf...

Page 15: ... mentioned and one comprised of series capacitor Cs and total equivalent shunt resistance Ri This new cutoff frequency is Equation 3 s i o C R 16 f To avoid compromise of the low frequency response established by the charge amplifier parameters and illustrated by Equation 2 the product of RiCs should be several orders of magnitude higher than RfCf The approximate final system discharge time consta...

Page 16: ...ss checking against other equipment manufacturer recommendation and any risk associated with incorrect readings International standards such as ISO 10012 1 provide insight and suggested methods for determining recalibration intervals for most measuring equipment With the above information in mind and under normal circumstances PCB conservatively suggests a 12 to 24 month recalibration cycle for mo...

Page 17: ...may be automated and vary depending on the type and number of accelerometers being calibrated Figure 2 Typical Back to Back Calibration System Because the acceleration is the same on both sensors the ratio of their outputs VT VR must also be the ratio of their sensitivities With the sensitivity of the reference standard SR known the exact sensitivity of the test sensor ST is easily calculated by u...

Page 18: ...e 4 Typical Calibration Set Up Adhesively mounted sensors use similar practices However in this case a small portion of quick bonding gel or similar temporary adhesive is used to attach the test sensor to a reference standard designed with a smooth flat mounting surface In addition to mounting the selection of the proper equipment is critical Some of the more important considerations include 1 the...

Page 19: ...ard Validate your calibration system with another accelerometer prior to each calibration session Check with the manufacturer for exact system specifications 7 5 CONCLUSIONS Without an adequate understanding of dynamics determining what when and how to test a sensor is a difficult task Therefore each user must weigh the cost time and risk associated with self calibration versus the services of an ...

Page 20: ... Height x Length x Width 40 in x 55 in x 50 in 10 2 mm x 14 0 mm x 12 7 mm Weight without cable 35 oz 10 gm 1 Electrical Connector Integral Hardline Cable Integral Hardline Cable Cable Length 10 ft 3 05 m 3 Cable Type MI Hardline Cable MI Hardline Cable Cable Termination 10 32 Coaxial Jack 10 32 Coaxial Jack Mounting Thread 5 40 Female 5 40 Female 5 All specifications are at room temperature unles...

Page 21: ...5 NJF 11 18 19 JDM 11 18 19 BAM 11 18 19 DIRECTION OF ACCELERATION TO PROVIDE A POSITIVE OUTPUT SIGNAL 65007 PCB Piezotronics Inc claims proprietary rights in the information disclosed hereon Neither it nor any reproduction thereof will be disclosed to others without the written consent of PCB Piezotronics Inc REVISIONS REV DESCRIPTION DIN B ADDED DIMENSIONS TO SHOW THREADED HOLE LOCATION 50197 55...

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