Significance and Use
This test method permits testing of the major components of an insulated digger derrick shown in Table 1 under controlled loading. The test method provides a means of detecting acoustic emissions generated by the rapid release of energy from localized sources within the digger derrick under controlled loading. The energy releases occur during intentional application of a predetermined load. These energy releases can be monitored and interpreted by qualified individuals. Acceptance/rejection criteria are beyond the scope of this test method. The test may be discontinued at any time to investigate a particular area of concern, or to prevent a fault from continuing to ultimate failure of the digger derrick resulting from the application of the test load.
This test method provides a means of detecting acoustic emission sources that may be defects, irregularities, or both, affecting the structural integrity or intended use of the aerial personnel device.
Significant sources of acoustic emission found with this test method shall be evaluated by either more refined acoustic emission test techniques or by other nondestructive methods (visual, liquid penetrant, radiography, ultrasonic, magnetic particle, etc.). Other nondestructive methods may be required in order to precisely locate defects in the digger derrick, and to estimate their size. Additional tests are outside the scope of this test method.
Defective areas found in digger derricks by this test method should be repaired and retested as appropriate. Repair procedure recommendations are outside the scope of this test method. Repair procedure recommendations are outside the scope of this test method.
|Component||To be Monitored in 11.1|
|Upper Boom Tip||A|
|Intermediate Boom(s), if equipped||C|
|Lower Boom Lift Cylinder Attach Bracket||E|
1.1 This test method covers a procedure for acoustic emission (AE) testing of digger derricks.
1.1.1 Equipment Covered—This test method applies to special multipurpose vehicle-mounted machines, commonly known as digger derricks. These machines are primarily designed to dig holes, set poles, and position materials and apparatus.
18.104.22.168 Insulated and non-insulated type digger derricks may be evaluated with this test method.
22.214.171.124 Digger derricks, if so equipped to position personnel or equipment, or both, may also be evaluated with this test method in conjunction with Test Method F914.
1.1.2 Equipment Not Covered—Excluded from this test method are general-purpose cranes designed only for lifting service and machines primarily designed only for digging holes.
1.2 The AE test method is used to detect and area-locate emission sources. Verification of emission sources may require the use of other nondestructive test (NDT) methods, such as radiography, ultrasonic, magnetic particle, liquid penetrant, and visual inspection.
1.3 Warning—This test method requires that external loads be applied to the superstructure of the vehicle under test. During the test, caution must be taken to safeguard personnel and equipment against unexpected failure or instability of the vehicle or components.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
FIG. 1 Insulated Digger Derrick Nomenclature