C1222, Section 7.2.5 contains requirements for inspection of the apparatus specified in C185 every 2 years. This ballot adds that language into C185 so that all users of C185 have the same equipment requirements and moves the calibration procedure from a note, making it mandatory. The requirement stated in C1222 is as follows: 7.2.5 Air content measures (400 mL) shall be calibrated at least every 2 1/2 years following the procedures described in Test Method C 185. In a previous ballot item, a negative voter pointed out that the procedure being described in C185 is not calibration. Review of the C125 definition calibration and verification (see below) led the subcommittee to conclude that the verification is more appropriate. The results of the previous ballot and agreement of the subcommittee is the reason for the concurrent ballot. verication, nof measuring instrument, provision of objective evidence to conrm that values indicated by a measuring instrument or system are within a specied range of known values of a reference standard. (2011) calibration, nof measuring instrument, a process that, under specied conditions and following a standard procedure, establishes metrological traceability by determining: (1) the relationship between the quantity values provided by measurement standards or certied reference materials and the corresponding indications from a measuring instrument or system; and (2) the estimated uncertainty of measurements made subsequently with the instrument or system. (2011) DISCUSSIONCalibration takes into account systematic error (or bias) of the measuring instrument or system as well as random error that is associated with the use of the measurement instrument or system and error associated with the measurement standards or certied reference materials. Calibration should not be confused with an adjustment of a measuring instrument or with verication of a measuring instrument. Sometimes the rst step alone is mistakenly called calibration, but performing only the rst step is the process of standardization. In tests of concrete and concrete aggregates, standardization of measuring instruments or systems is often sufficient.
Keywordsair content; hydraulic cement mortar; Air entrainment; Cement mortars; Hydraulic cement concrete;
Ballot Item Approved as C185-2015A and Pending Publication