Usgs Reference Materials Manufacturer – National Certified Reference Material (NCRM) – Shandong Institute of Metallurgical Science

The CRM is used for the verification/calibration of oxygen bomb calorimeter. It is also used for the evaluation and verification of accuracy of the analytical methods. The CRM can be used for calorific value measurement in electric power, coal, military industry, scientific research and other fields.

Benzoic acid is purified by distillation and the purity is 99.96%. It is made into about 0.5g tablets and packed in clean plastic bottles.

Table 1. Certified Values for Benzoic Acid

The bomb calorimeter is used to make these measurements.

Twenty bottles are randomly selected to determine the measurement order. An analysis specimen is selected from each bottle, and the method is the bomb calorimeter. Variance (F) test is used to evaluate the uniformity of the CRM, when the F<F_α, sample are homogeneous.

Expiration of certification: The certification of this CRM is valid until February 1, 2031.

The certified reference material is packed in plastic bottles with plastic covers. The net weight is about 35g each bottle. It is suggested to keep dryness when stored.