GeoSIG | Seismometer, accelerometer, SHM, and other earthquake monitoring and measuring solutions
User Manual for GeoSIG models including: AC-43 MEMS Accelerometer, AC-43 MEMS, Accelerometer
GeoSIG AC-4x Accelerometer
GeoSIG AC-43 Accelerometer
File Info : application/pdf, 13 Pages, 820.54KB
DocumentDocumentUser Manual AC-43 MEMS Accelerometer Author: Checked: Approved: Distribution: Serge Rudaz Talhan Biro Johannes Grob GeoSIG Ltd (1), Customer on request GeoSIG Ltd, Wiesenstrasse 39, 8952 Schlieren, Switzerland Phone: + 41 44 810 2150, Fax: + 41 44 810 2350 info@geosig.com, www.geosig.com User Manual AC-43 Accelerometer 11.08.2022 / V07 2 / 13 DOCUMENT REVISION Version 1 2 3 4 5 6 7 Date 12.2.2007 25.02.2008 23.09.2013 06.06.2014 07.05.2019 24.02.2022 04.08.2022 Modification Adapted to new sensor housing File name and title change Updated with DH version. Axis orientation New logo Mounting section updated Housing drawing updated Updated chapter 2, electrical connector Changed chapter order Updated document revision table Prepared Checked Released SR SR JLT VAG VAG KEC TB TB MAE ALB ALB ALM ALB KEC Disclaimer GeoSIG Ltd reserves the right to change the information contained in this document without notice. While the information contained herein is assumed to be accurate, GeoSIG Ltd assumes no responsibility for any errors or omissions. Copyright Notice No part of this document may be reproduced without the prior written consent of GeoSIG Ltd. Software described in this document is furnished under a license and may only be used or copied in accordance with the terms of such a license. Trademark All brand and product names mentioned are trademarks or registered trademarks of their respective holders. All rights reserved. GeoSIG Ltd Switzerland GS_AC-43_UserManual_V07 User Manual AC-43 Accelerometer 11.08.2022 / V07 3 / 13 TABLE OF CONTENTS WARNINGS AND SAFETY................................................................................................................................3 1 BASIC SPECIFICATIONS ........................................................................................................................4 2 ELECTRICAL CONNECTOR....................................................................................................................4 2.1 BINDER SERIE 623...................................................................................................................................4 2.2 BINDER SERIE 423...................................................................................................................................5 2.3 CONNECTOR PIN DESCRIPTION ................................................................................................................5 3 MOUNTING ...............................................................................................................................................6 4 THEORY OF OPERATION .......................................................................................................................7 4.1 INTRODUCTION ........................................................................................................................................7 4.2 PRINCIPLE ...............................................................................................................................................7 5 ELECTRICAL CONFIGURATION.............................................................................................................8 6 MOUNTING (DOWNHOLE SENSOR) ......................................................................................................8 6.1 BOREHOLE PREPARATION.........................................................................................................................8 6.2 INCLINOMETER TUBE INSTALLATION...........................................................................................................9 6.3 SENSOR INSTALLATION...........................................................................................................................10 6.4 INCLINOMETER CASING ASSEMBLY ..........................................................................................................11 6.5 AXIS ORIENTATION .................................................................................................................................13 7 INSTALLATION VERIFICATION ............................................................................................................13 Warnings and Safety a The sensor housing provides no protection against explosive atmosphere. It must not be directly operated in area where explosive gases are present. GS_AC-43_UserManual_V07 User Manual AC-43 Accelerometer 11.08.2022 / V07 1 Basic specifications Sensor Series Input range Output range Frequency range Protections Power supply Current drain AC-43 Acceleration, ±0.625, ±1, ±2, ±3, ±4 or ±5 g 0 ± 10 Volt differential output From DC to 100 Hz All connectors pins protected by Transzorb diodes and VDR 7 15 VDC Average 74.1 mA @ 15 VDC 4 / 13 2 Electrical Connector All the AC-4x accelerometers are supplied as standard with a 2 m connection cable. Based on the intended use, the 12-pin metallic-style connectors will be supplied in one of the following options: Binder Serie 623 or Binder Serie 423. 2.1 Binder Serie 623 GeoSIG Binder Serie 623 P/N #J_CIR.012.002.F P/N 99 4622 00 12 Figure 1, Binder Serie 623 Connector Cable gland nut has to be determined as per cable external diameter and must be separately ordered. It has also to provide the cable shield connection to connector case. GS_AC-43_UserManual_V07 User Manual AC-43 Accelerometer 11.08.2022 / V07 2.2 Binder Serie 423 GeoSIG Binder Serie 423 P/N #J_CIR.012.010.M P/N 99 5629 00 12 5 / 13 Figure 2, Binder Serie 423 connector Cable gland nut has to be determined as per cable external diameter and must be separately ordered. It has also to provide the cable shield connection to connector case. 2.3 Connector Pin Description The connector pin assignment and cable colour code can be observed in the table below: Binder Connector Serie 623 Serie 423 SIGNAL Comment Colour Pinout Pinout 1 A OUTPUT X (+) 0 V ± 5 V voltage output, 47 output impedance White 2 B OUTPUT X (-) 0 V ± 5 V voltage output inverted, 47 output impedance Brown 3 C OUTPUT Y (+) 0 V ± 5 V voltage output, 47 output impedance Green 4 D OUTPUT Y (-) 0 V ± 5 V voltage output inverted, 47 output impedance Yellow 5 E OUTPUT Z (+) 0 V ± 5 V voltage output, 47 output impedance Grey 6 F OUTPUT Z (-) 0 V ± 5 V voltage output inverted, 47 output impedance Pink 7 G TEST INPUT Test input, output will result in a sensor step response Blue 8 H GND Connected to Recorder's GND Red 9 J +12 VDC power Power input, +7 to +15 VDC range, 74.1 mA @ 15 VDC Black 10 K GROUND Ground, not connected to mechanical ground Violet 11 L AUX Auxiliary input (reserved) Grey/Pink 12 M GROUND Ground, not connected to mechanical ground Red/Blue Table 1. AC-4x Connector Pin Assignment and Cable Colour Code GS_AC-43_UserManual_V07 User Manual AC-43 Accelerometer 11.08.2022 / V07 3 Mounting 6 / 13 Figure 3, AC-4X housing Small size and single bolt attachment allow the AC-4X to be easily installed saving installation time. Levelling is accomplished via three-point levelling screws. a Do not overtighten the three-point levelling mechanism. This may damage the sensor. Figure 4, Sensor housing dimensions GS_AC-43_UserManual_V07 User Manual AC-43 Accelerometer 11.08.2022 / V07 7 / 13 The accelerometers must be firmly mounted to a surface and levelled, as the application requires. Check to be sure that the accelerometer is aligned to produce the desired output signals. Acceleration in the direction indicated on the case will produce a positive output signal. The orientation definitions as shipped are: X = East, Y = North and Z = Vertical (Up). The accelerometer has single-bolt, 3-feet-levelling mechanism. The surface should have a scribed north/south orientation line accurately surveyed from reliable markers. The X-axis of the sensor has to be pointed to East or to any other main direction of the structure to monitor. One M8 expanding nut rock anchor must be used for the sensor fixation. 4 Theory of operation 4.1 Introduction The AC-43 sensor package is a triaxial accelerometer designed for free field and industrial applications regarding STRONG-MOTION earthquake survey, monitoring and research. This sensor is well suited for applications where a high sensitivity is required. The AC-43 sensor can be optionally installed into a rugged protective housing. This optional protective housing is in stainless steel for optimal environmental resistance. As option, the protective housing could be executed with an IP68 grade for Free field location where the possibility exists of housing submersion. The sensor could be installed on floor or wall with a modification of the axis organization. With the help of the TEST LINE, the complete sensor can be very easily completely tested. Full scale can be field selected by the user with jumpers. 4.2 Principle The AC-43 accelerometer is based on the modern MEMS (Micro Electro-Mechanical Systems) technology, consisting of sensing cells assembled in a way that optimizes their performances. This combined with the state of the art proprietary circuit design yields this cost effective and reliable accelerometer. MEMS cells include linear accelerometer sensing elements which measure the capacitance variation in response to any movement or inclination and a factory trimmed interface chip that converts the capacitance variations into analog or digital signal proportional to the motion. The DC response allows the sensor to be easily repaired, tilt tested or recalibrated in the field. With the help of the TEST LINE the AC-43 accelerometer can be completely tested assuring proper operation. S1 x OUTPUT STAGE S2 x Charge S/ amplifier S1 y MUX DE-MUX S/ R S2 y S/ Vout X Vout Y Vout Z S1 z SELF TRIMMING VOLTAGE AND CLOCK AND TEST CIRCUIT CURRENT PHASES REFERENCES GENERATOR S2 z Figure 5 AC-43 Sensor block diagram The test signal will move the seismic mass. The movement of the mass generates a voltage across the position detector, which is detected by the differential charge amplifier and induces an output signal. GS_AC-43_UserManual_V07 User Manual AC-43 Accelerometer 11.08.2022 / V07 8 / 13 5 Electrical configuration The full scale can be only adjusted by the mean of the gain potentiometer for each axis. The offset can be at any time readjusted for each channel with a potentiometer without gain re-calibration 6 Mounting (downhole sensor) The sensor must be installed in a 3-inch inclinometer tube. At least a 100 mm borehole must be drilled. Depending on the soil condition, it could be required to drill a higher dimension hole and to implement a 120 mm PVC casing to insure a free path when the inclinometer tube is inserted in the borehole. 6.1 Borehole preparation Note: Do not scale the drawing. Surface level 12 cm Depth of drilled borehole PVC tubing Minimum free diameter inside casing: 120 mm. Casing sealing Cap Figure 6 Borehole Preparation Do not allow concrete mix from casing sealing to enter the casing. GS_AC-43_UserManual_V07 User Manual AC-43 Accelerometer 11.08.2022 / V07 6.2 Inclinometer tube installation Note: Do not scale the drawing. The number of section is only an example. 9 / 13 3 meters 30 cm Inclinometer tube in 3 meters section. Sealing (concrete mix) of tube Coupling elements, fixed with "pop" rivets. Must be fully sealed to avoid any concrete inside the tube. Figure 7 Inclinometer tube installation Bottom cap. Must be fully sealed to avoid any concrete inside the tube. GS_AC-43_UserManual_V07 User Manual AC-43 Accelerometer 11.08.2022 / V07 10 / 13 6.3 Sensor installation Note: Do not scale the drawing. The number of sections is only an example. 50 m maximum About 170 cm About 70 cm Cable The maximum water level above the sensor must be maximum 50 meters. Concrete sealing of sensor. At least 1 meter above the sensor. Sensor AC-43-DH, diameter 54 mm. Guiding system Sand (50 cm) Figure 8 Sensor Installation GS_AC-43_UserManual_V07 About 50 cm User Manual AC-43 Accelerometer 11.08.2022 / V07 11 / 13 6.4 Inclinometer casing assembly The borehole must have a casing or the soil must insure that a free path for the inclinometer tube is warranted. It is recommended to insert the inclinometer tube as soon the borehole is ready. The free path for the inclinometer tube should be 10 to 15 cm, 12 cm typically. It could be required to insert some water in the casing to sustain the water pressure at the bottom of the borehole. The inclinometer tube should be mounted with a maximum deviation of ±1° / 3 meters and with a maximum deviation from vertical at sensor location of ±3°. The functional limit for the sensor is ±9°. The water level in the inclinometer tube should be maximum 50 meters, including fast elevation due to heavy rain. It is recommended to use the optional assembly kit that GeoSIG can provide (optional) with the inclinometer tube. It will insure a perfect sealing of the tube elements and would avoid concrete mix to enter the tube. The dimensions of the inclinometer tube are: Figure 9 Inclinometer tube dimensions INCLINOMETRIC CASING (3 m section) A Inner diameter 76.1 mm B Groove outer diameter 86.4 mm C Thickness 2.2 ±0.1 mm D Groove inner diameter 82.0 mm COUPLING ELEMENT A Inner diameter B Outer diameter C Thickness D Groove inner diameter Length Weight Borehole diameter 3 meters Length 1.4 Kg/m Weight > 120 mm Table 2 Inclinometer tube dimensions 81.0 mm 92.0 mm 2.2 mm 87.6 mm 300 mm 0.5 kg GS_AC-43_UserManual_V07 User Manual AC-43 Accelerometer 11.08.2022 / V07 13 The following elements will be inserted in the borehole: Figure 10 12 / Torpedo (the sensor and its cable) Figure 11 Figure 12 Guiding system Inclinometer tube GS_AC-43_UserManual_V07 User Manual AC-43 Accelerometer 11.08.2022 / V07 13 / 13 6.5 Axis orientation Z axis X axis Y axis Engraved mark Figure 13, Down hole axis orientation Before the sensor is inserted in the inclinometer tube, the guiding system must be mounted bellow it. The guiding system must be orientated before the insertion. The engraved mark on bottom cover is showing the positive direction of X axis: Z axis: Vertical, positive up Y axis X axis Mark View for top: 7 Installation Verification Please note that temperature compensation device is mounted for each axis inside the sensor and that the temperature in the sensor has to stabilize before accurate measurement can be done. Allow at least half an hour for temperature stabilization. GS_AC-43_UserManual_V07