JJF 1846-2020Calibration Specification for Chute Weighing Instruments (English PDF)

1 Scope (1)

2 Reference documents (1)

3 Terms and measurement units (1)

4 Overview (2)

5 Measurement characteristics (2)

6 Calibration conditions (3)

7 Calibration items and calibration methods (3)

8 Calibration result expression (6)

9 Recalibration interval (6)

Appendix A Recommended Format of Calibration Original Record (7)

Appendix B Recommended Format of the Internal Page of the Calibration Certificate (8)

Appendix C Example of Uncertainty Evaluation of Indication Error of Material Test (9)

Introduction

JJF 1001-2011 "General Metrology Terms and Definitions", JJF 1059.1-2012 "Measuring Uncertainty Evaluation and Representation" and JJF 1071-2010 "Rules for the Compilation of National Metrology and Calibration Specifications" together constitute the support for the formulation of this specification the basic series of specifications.

This specification is released for the first time.

Calibration Specification for Chute Scale

1 Scope

This specification applies to the use of gravity and/or impulse principles to determine and accumulate bulk materials in a continuous weighing method Calibration of quality chute scales.

This specification does not apply to the calibration of chute scales whose measuring element is a differential pressure transmitter.

2 Reference documents this specification refers to the following documents.

JJF 1181 Weighing instrument measurement terms and definitions GB/T 35593 Chute scale for dated reference documents, only the dated version applies to this specification; for undated reference documents, the latest version (including all amendments) is applicable to this specification.

3 Terms and units of measurement

3.1 Term

The following terms and definitions defined by JJF 1181 and GB/T 35593 apply to this code.

3.1.1 Chute scale

An automatic weighing instrument that continuously weighs the bulk materials sliding through the chute without subdividing the quality category.

3.1.2 Maximum flow

The flow rate derived from the maximum carrying capacity of the gravity measuring unit and the impulse measuring unit of the chute scale is Qmax.

3.1.3 Minimum flow

The lower limit of flow measurement that can ensure compliance with the specified relative error requirements, the symbol is Qmin.

3.1.4 Feeding flow

The flow of material from the previous device to the guide chute.

3.1.5 Cumulative division value in the normal weighing mode of the chute scale, the total cumulative display or partial cumulative display shows the difference between two adjacent values in mass units, and the symbol is dt.

3.1.6 Minimum cumulative load the quantity expressed in mass units can guarantee the minimum cumulative value of the chute scale that meets the specified relative error requirements. The symbol is sum min.

3.1.7 Gravity measurement unit A device that provides information on the weight of the measured load on the chute scale. The gravity measurement unit consists of a gravity chute and a gravity measurement sensor.