102 Consider the larger of the warpage figures as that of the specimen Report

# 102 consider the larger of the warpage figures as

• 4

This preview shows page 3 - 4 out of 4 pages.

10.2 Consider the larger of the warpage figures as that of the specimen. Report the warpage values for the individual speci- mens to two significant figures. SQUARENESS OF REFRACTORY BRICK 11. Apparatus 11.1 Metal Plate , 24 by 24 by 1-in. (610 by 610 by 25 mm) thick, with one surface ground to a flatness of 6 0.005 in. (0.13 mm), or an equivalent abrasion-resistant flat surface. 11.2 Precision Square , 12 by 9 in. (305 by 229 mm). 11.3 Measuring Wedge , steel, 2.5 in. (64 mm) long by 0.5 in. (13 mm) wide by 0.5 in. thick at one end, and tapered from a line 0.5 in. at one end to zero thickness at the other end. The wedge shall be graduated and numbered along the slope to show the thickness of the wedge between base AB and slope AC in 0.02 in. (0.5 mm) division (Fig. 1). 12. Procedure 12.1 Place the test specimen on the metal plate so that it rests securely on a width face (Fig. 5). 12.2 Abut the square at about midpoint of the long dimen- sion. 12.3 Insert the steel wedge at the point of maximum departure between the square and brick surface (Fig. 5). 12.4 Read and record the deviation to the nearest 0.02 in. (0.5 mm). 12.5 Repeat the procedures in 12.2, 12.3, and 12.4 for the opposite vertical face and each end. 12.6 Reposition the specimen to rest securely on a thickness face. 12.7 Repeat the procedures in 12.2, 12.3, and 12.4 for both major vertical faces and each end. 13. Report 13.1 Report the following: 13.1.1 Brick brand and nominal size. 13.1.2 Individual deviation obtained from each measured face for each specimen in the sampling. 14. Precision and Bias 14.1 Precision : 14.1.1 Interlaboratory Test Program —An interlaboratory study was conducted by six laboratories on ten specimens using two replications and two duplicate runs on the same specimen. The specimens were stiff mud extruded and pressed super duty brick. 14.1.2 Repeatability —The maximum permissible difference due to test error between two test results obtained by one operator on the same material is given by the repeatability interval and the relative repeatability interval (coefficient of variation). The 95% repeatbility intervals are given in Table 1. Two test results that do not differ by more than the repeatability interval will be considered the same, and, conversely, two test results that do differ by more than the repeatability interval will be considered different. 14.1.3 Reproducibility —The maximum permissible differ- ence due to test error between two test results obtained by two operators in different laboratories on the same type of material FIG. 3 Method of Measuring Warpage of a Convex Surface FIG. 4 Alternative Method of Measuring Warpage of a Convex Surface A —Width face B —Thickness face C —End face FIG. 5 Method of Measuring Squareness C 134 3
using the same type of test equipment is given by the reproducibility interval and relative reproducibility interval (coefficient of variation). The 95% reproducibility intervals are given in Table 1. Two test results that do not differ by more than the reproducibility interval will be considered the same and, conversely, two test results that do differ by more than the reproducibility interval will be considered different.

#### You've reached the end of your free preview.

Want to read all 4 pages?

• Spring '18
• Height, Test method, Standard, refractory brick

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern