The 5-660 Standard Magne-Gage is used for all general flat and curved surface work with which the gauge head can be lowered directly onto the point of measurement. (Maximum depth 11/16"; for depressions of greater depth the 5-686 Extended Guard Magne-Gage is indicated. Table I lists the combinations of magnets and calibrations available with the 5-660 Standard Magne-Gage . Diagram of the Magne-Gage
The 5-686 Extended Guard Magne-Gage is designed for measuring coating thickness' where (because of the specimens shape or size) the surface to be measured cannot be brought into contact with the magnet of the Standard instrument (for example, beyond a boss or in a depression). To solve this problem, the magnet guard, which normally extends 11/16 inch below the lower part of the gauge (see the diagram above) is lengthened up to 3 1/16 inches. A guard of any length between the standard 11/16 inch and the maximum 3 1/16 inches can be supplied. The length of the magnet will be increased proportionately to match the length of the extended guard. When ordering, please specify the overall length of the extension desired. Table II lists the combinations of magnets and calibrations available with the 5-686 Extended Guard Magne-Gage.
The 5-660 Standard, or 5-686 Extended Guard Magne-Gage may be used to measure various types of coatings in one or more thickness ranges by using the magnet and calibrations noted in Table I and Table II. Before shipping, each Magne-Gage is calibrated with the master thickness standards prepared and certified by the National Institute of Standards and Technology, which must be ordered with the instrument. A calibration consists of one calibration curve, drawn for each specific gauge and magnet, and one card of four thickness standards, each of known thickness. These cards are furnished to permit periodic checking of the instruments calibration. When ordering, select a combination from the applicable table, and note the catalog numbers for the magnet and calibrations selected.
Magnets and calibrations shown below are for use with the 5-660 Standard Magne-Gage. BOTH magnet catalog and calibration catalog number must be shown when ordering.
Ordering Information for 5-660 Standard Magne-Gage
Magnets and calibrations shown below are for use with the 5-686 Extended Guard Magne-Gage. BOTH magnet catalog number and calibration catalog must be shown when ordering. Also, specify guard length.
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| Ordering Information for 5-686 Extended Guard Magne-Gage
The 5-660 Standard Magne-Gage includes the basic instrument, carrying case and instructions. Magnets and calibrations as specified in Table I must be ordered separately; see the explanation listed above and the catalog listings below.
Magnets for use with the 5-660 Standard Magne-Gage are as defined in Table I. Extra and replacement magnets are supplied magnetized and stabilized for use on the Magne-Gage. Note: Each time a replacement magnet or set of standards is purchased, the Magne-Gage should be returned to the factory for recallibration to factory O.E.M. specifications.
Calibrations consist of a card of 4 National Institute of Standards Technology (NIST) certified thickness standards and a calibration curve plotted for a specific gauge and magnet combination. The calibration curve is required to regularly recheck the specific gauge and magnet to assure that the magnet has not been altered and that the gauge is operating properly. Substitution of another magnet or alteration of the gauge balance will require recalibration. Order by the noted catalog numbers to obtain proper calibrations specified in Table I for the coating and thickness' to be measured.
The 5-686 Extended Guard Magne-Gage can be used with magnets 1, 2, 3 and 4, and calibrations A, B, C, D, E, and H in the arrangements defined in Table II. Gauge is provided less magnets and calibrations which must be ordered separately. (Thickness Standards supplied with the Extended Guard Magne-Gague are the same as those supplied with the Standard Magne-Gage. Magnets for use with the 5-686 Extended Guard Magne-Gage are as defined in Table II. Extra and replacement magnets are supplied magnetized and stabilized for use on the Magne-Gage. Note: Each time a replacement magnet or set of standards is purchased, the Magne-Gage should be returned to the factory for recallibration to factory O.E.M. specifications. When ordering replacement magnets, please specify number of gauge and overall length of magnet including extensions, or specify the length of the guard with which the magnet is to be used. Order by catalog numbers listed below:
The Magne-Gage apparatus is specified by the Welding Research Council for the measurement of Delta-Ferrite in austenitic weld metal and castings in the range between 2 to 28 ferrite number. In the approximate range of ferrite numbers 2 to 10 the Delta-Ferrite percentage and ferrite number are interchangeable. These recommendations are based on several technical papers (available in reprints) and extensive round-robin testing in which a relationship was established between the attraction of Magne-Gage apparatus magnet number 3w (J5-066w) and number 2w (J5-0664w) magnet to the J5-0668D and J5-0668H NIST Thickness Standards. Secondary weld pad Standards may also be used.
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