1、Designation: D 7299 06Standard Practice forVerifying Performance of a Vertical Inclinometer Probe1This standard is issued under the fixed designation D 7299; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision
2、. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice describes three function tests that togethercan be used to verify that a vertical inclinometer probe isworking prope
3、rly.1.2 This practice does not address calibration routines,electronic diagnostics, or repair of the probe, nor does itaddress inspection of the probes mechanical parts.1.3 This practice is not intended to replace manufacturersrecommendations for servicing and calibration of inclinometerequipment, n
4、or is it intended to replace maintenance andcalibration schedules established by users as part of theirquality programs.1.4 This practice offers a set of instructions for performingone or more specific operations. This document cannot replaceeducation or experience and should be used in conjunctionw
5、ith professional judgment. Not all aspects of this practice maybe applicable in all circumstances. This ASTM standard is notintended to represent or replace the standard of care by whichthe adequacy of a given professional service must be judged,nor should this document be applied without considerat
6、ion ofa projects many unique aspects. The word “standard” in thetitle of this document means only that the document has beenapproved through the ASTM consensus process.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of
7、 the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 653 Terminology Relating to Soil, Rock, and ContainedFluidsD 3740 Practice for Minimum Requirements fo
8、r AgenciesEngaged in the Testing and/or Inspection of Soil and Rockas Used in Engineering Design and Construction3. Terminology3.1 DefinitionsTerms not defined below may appear inTerminology D 653.3.1.1 inclinometer casing, nA special-purpose pipe, typi-cally installed in boreholes, with internal gu
9、ide grooves thatcontrol the orientation of the inclinometer probe and thatprovide a flat surface for repeatable tilt measurements.3.1.2 survey, nA set of readings obtained with the incli-nometer probe and readout.3.1.3 vertical inclinometer probe, nA wheeled deviceused to measure the tilt of inclino
10、meter casing that is installedin a vertical borehole. The wheels of the device track thegrooves of the inclinometer casing and also keep the body ofthe probe centralized within the casing. Typically there are twosensors inside the device, each capable of reporting positiveand negative values. One se
11、nsor measures tilt in the plane ofthe wheels and is commonly known as the A-axis sensor. Theother sensor measures tilt in the plane normal to the wheels andis commonly known as the B-axis sensor.3.1.4 zero offset, nNon-zero values reported by the A-axisand B-axis sensors when the probe is held preci
12、sely vertical.4. Significance and Use4.1 Inclinometer monitoring programs often run severalyears or more. During this time, hundreds of surveys can becollected. Each new survey is processed by comparing it to abaseline survey.4.2 Over a period of years, normal wear and tear cangradually degrade the
13、probes ability to produce new surveysthat are directly comparable to the baseline survey. This maygo unnoticed for some time, because the quality of readingsmay degrade in very small increments.4.3 When function tests are incorporated into an inclinom-eter monitoring program, the degradation of read
14、ing qualitycan be avoided. Probes that pass the tests can be used withconfidence. Probes that fail the tests should be returned to theprobe manufacturer for servicing. It should be noted thatmanufacturers calibrate inclinometer probes using high-precision, electronically-controlled equipment in temp
15、erature-controlled environments. Ordinary users do not have access tosuch equipment, so the pass/fail criteria suggested for these1This practice is under the jurisdiction of ASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.23 on Field Instrumen-tation.Current e
16、dition approved Nov. 1, 2006. Published December 2006.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandardsvolume information, refer to the standards Document Summary page onthe ASTM website.1Copyrig
17、ht ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.tests accommodate typical results produced by less preciseequipment in a less controlled environment.4.4 The quality of the result produced by this standard isdependent on the competence of the
18、 personnel performing itand the suitability of the equipment and facilities used.Agencies that meet the criteria of Practice D 3740 are generallyconsidered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautionedthat compliance with Practice D 3740 doe
19、s not in itself assurereliable results. Reliable results depend on many factors;Practice D 3740 provides a means of evaluating some of thosefactors.5. Apparatus5.1 Two pieces of equipment are suggested: a rotary tabletest stand and a test casing. All the tests could be performedusing only the rotary
20、 table test stand, but operation of the rotarytable requires a trained operator working slowly and deliber-ately. The test casing, on the other hand, provides a simple testthat can be used frequently by any inclinometer user after a fewminutes of training.5.2 Rotary Table Test Stand5.2.1 The rotary
21、table test stand (Fig. 1) consists of a rotarytable mounted on a pedestal. The rotary table is a device that iscommonly used in precision machining operations. In machineshops, rotary tables are usually mounted horizontally. In thiscase, the table is mounted vertically, so that it can move theprobe
22、through its specified tilt range. A suitable rotary tablewill offer a placement accuracy of 30 seconds of arc or betterthroughout its range. It should provide an adjustable dial on thehand wheel that reads directly to each minute of arc, and avernier plate that permits direct reading to within 5 s.
23、Thevernier scale is used to make the various test measurements.5.2.2 Make the pedestal from a steel I-beam or a 6-inch (150mm) diameter steel pipe cut to a convenient height. Steel is acommonly available material but other metals may be also besuitable. Make plates for the top and bottom of the pede
24、stalusing 0.5-in. (12.5 mm) thick steel. Mill the top plate flat forproper mounting of the rotary table. Drill bolt holes in the baseplate, as shown in Fig. 1. Weld the steel plates to the two endsof the beam or pipe. Choose a location for the stand and setbolts into stable flooring, such as a concr
25、ete floor slab. Ideally,the location will be free from vibration. Place the test standonto the bolts. Place steel shims under the bottom plate so thatthe top plate is completely horizontal, as indicated by amachinists bubble level. Tighten nuts on the floor bolts.5.2.3 Mount the rotary table to the
26、top plate as shown inFigure 1. Place steel shims as necessary to make the plane ofthe table vertical. Make a probe holder from 2-in. (50 mm)square-section 6061 T6 aluminum tubing. The square sectiontubing holds the wheels tightly, in a fixed, repeatable position.Inclinometer casing is not a suitable
27、 substitute for the tubing,since casing grooves are purposely made wider to facilitatepassage of the probe through deformed casing. Mount theprobe holder to the rotary table using two V-blocks, fitting theholder so that it provides two possible positions for the probe,one parallel to the rotary tabl
28、e, and the other perpendicular tothe table.5.2.4 Devise a means of applying a constant torque to thetable to compensate for backlash in the gears and improve theprecision with which the table can be rotated. Fig. 1 shows aweight suspended from a wire rope that is attached to the table.Wrap the wire
29、rope over the top of the table so that the weightassists rotation toward positive angles (typically clockwise) asread from the scales on the rotary table.5.3 Test Casing5.3.1 The test casing (Fig. 2) consists of a short length ofinclinometer casing, a steel pipe of sufficient diameter to holdinclino
30、meter casing, and a square steel base plate that can besecured to bolts set into a concrete floor slab.5.3.2 Drill bolt holes in the base plate. Weld the steel pipeto the base plate. Attach a bottom cap to the inclinometerFIG. 1 Rotary Table Test StandD7299062casing and seal it so that grout will no
31、t enter. Place inclinom-eter casing inside the steel pipe.Align the casing so that its fourguide grooves point to the four sides of the base. Use cementgrout to fix the casing within the pipe.5.3.3 Place the completed test casing onto the floor bolts,but do not tighten the nuts yet.5.3.4 Choose one
32、of the four grooves in the casing to be theA+ groove. Mark it as theA+ groove. The B+ groove is located90 clockwise. Mark it as the B+ groove.5.3.5 Connect the probe to the readout, and turn on thepower. Orient the probe so that the upper wheels of both wheelsets are aligned with the A+ groove, and
33、insert the probe intothe casing. Allow the probe 10 minfor warm up.5.3.6 Calculate what value on the display is the equivalentof 1. Use the manufacturers instrument constant to convertfrom display units to degrees. Tilt the test casing until thedisplay shows the equivalent of 1 tilt in both the A+ a
34、nd B+directions. Place steel shims under the base plate to maintainthis tilt and then tighten the bolts. Installing the test casing withthis small tilt ensures that test readings will maintain theirexpected signs regardless of any zero offset in the sensors.6. Test of Repeatability6.1 This test veri
35、fies that the probe can provide repeatablereadings at a selected test angle after it has been moved throughits entire tilt range, which is nominally 630 for most probes.6.2 The test employs the rotary table test stand and requiresan understanding of the rotary table and how its scales are read.To ma
36、ke positioning of the table as precise as possible, alwaysapproach the test angle from the direction opposite that of theapplied torque of the suspended weight. In other words, if theapplied torque acts clockwise, approach the test angles via acounter-clockwise rotation. If a clockwise rotation is r
37、equiredto reach the test angle, then the table should be rotated throughthe test angle, passing it by about 20 arc-min, and then returnedto the test angle by a counter-clockwise rotation.6.3 Connect control cable to the probe and to the readout.Switch on the readout to provide power to the probe. Wa
38、it 10min, with the probe powered, before continuing the procedure.6.4 Begin the A-axis test. Hold the probe so that its wheelsare parallel with the rotary table and the upper wheel of eachwheel set is pointed toward the direction of positive angles.Insert the probe into the probe holder.6.5 Rotate t
39、he table to a starting point of -90. Now rotatethe table through the zero to about +1 20. Then slowly returnthe table to exactly +1. Do not overshoot the +1 mark. If thishappens, start again from the -90 position.6.6 With the table at exactly +1, record the reading. Thiswill be the target reading fo
40、r the subsequent steps.6.7 Rotate the table to a new starting point of +90. Thenrotate the table back toward +1. Watch the display and slowthe rotation speed as the target reading is approached. Continueuntil the target reading is displayed. If the target reading ismissed, start again from +90.6.8 W
41、ith the target reading displayed, check the vernierscale. It should show no more than 6 30 arc-seconds awayfrom +1. Repeat steps 3 through 5 to obtain a second set ofreadings. Again, the repeatability should be within 6 30arc-seconds from +1 on the vernier scale.6.9 Begin the B-axis test. Withdraw t
42、he probe from theholder, rotate it 90 counter clockwise, and reinsert it. Rotatethe table to the negative side of zero. The B-axis reading shoulda negative number. If it is not, withdraw the probe from itsholder, rotate it 180 and reinsert.6.10 Repeat steps 3 through 6 for the B axis. Use the samepa
43、ss/fail criterion of +/- 30 arc-seconds away from +1on thevernier scale.7. Test of Conformity7.1 This test verifies that the output of the probe at a giventilt is within acceptable tolerances.FIG. 2 Test CasingD72990637.2 The rotary table test stand is used for this procedure.Good control of the rot
44、ary table is required. Readings are takenat six test angles: +30, + 20, +10, -10 -20 -30.7.3 Connect control cable to the probe and to the readout.Switch on the readout to provide power to the probe. Wait 10min, with the probe powered, before continuing the procedure.7.4 Begin the A-axis test. Orien
45、t the probe so that its wheelsare parallel with the rotary table and slide it into the probeholder. Rotate the table to a starting point of +35.7.5 5 Rotate the probe to +30, wait for the reading tostabilize, and record the reading.7.6 Rotate the probe to +20, wait for the reading tostabilize, and r
46、ecord the reading.7.7 Rotate the probe to +10, wait for the reading tostabilize, and record the reading.7.8 Rotate the probe to -10, wait for the reading tostabilize, and record the reading.7.9 Rotate the probe to -20, wait for the reading tostabilize, and record the reading.7.10 Rotate the probe to
47、 -30, wait for the reading tostabilize, and record the reading.7.11 Calculate the algebraic differences for readings at thesame magnitude of tilt, and then divide the difference by 2. Forexample, subtract the reading taken at -30 from the readingtaken at +30 and divide the result by 2. This operatio
48、neliminates zero-offset values from the readings and is consis-tent with the way that inclinometer data are normally pro-cessed.7.12 Convert the three values obtained in the step above todecimal degrees using constants provided by the manufacturerof the probe. The result should be three “reading ang
49、les” thatare approximately 30, 20, and 10.7.13 The difference between the reading angles obtainedabove and the test angles of 30, 20, and 10 should notexceed 0.15% of the test angle. If the error exceeds 0.15% ofthe test angle with repeated testing, the probe should bereturned to the manufacturer for testing and calibration.8. Test of Zero-Offset8.1 This test is used to monitor changes in the zero-offset ofthe sensor. Changes in the zero-offset value are commonthroughout the life of the probe, but are normally of noconcern, since the
