GB/T 22779-2026Liquid crystal display quartz clocks (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents".

This document replaces GB/T 22779-2017 "Liquid Crystal Quartz Clocks". Compared with GB/T 22779-2017, the only changes are structural adjustments and editing.

Aside from the sexual alterations, the main technical changes are as follows.

a) The "Voltage Range" has been changed (see 4.2, 3.2 in the 2017 version);

b) The test method for "instantaneous daily range m" has been modified, and the requirement and test method for "average instantaneous daily range m" have been removed (see 4.4, 5.4.4). (2017 versions 3.4 and 4.4.4)

c) The requirements for "temperature coefficient and voltage coefficient" have been changed (see Table 1, 2017 version of Table 1);

d) Requirements and test methods for the "voltage coefficient" have been added (see 4.6 and 5.4.6);

f) Requirements and test methods for "temperature and humidity functions" have been added (see 4.14 and 5.4.16);

g) Requirements and test methods for "communication functions" have been added (see 4.15, 5.4.17);

h) The "Test Instruments and Equipment" section has been changed (see Table 5, Table 4 in the 2017 edition).

1 Scope

This document specifies the technical requirements for liquid crystal quartz clocks (hereinafter referred to as "liquid crystal clocks"), describes the corresponding test methods, and specifies the inspection procedures.

This document applies to devices with quartz resonators, nominal operating voltages of DC 3.7V, DC 3.0V, or DC 1.50V, and displaying time and date information. LCD clock display or other additional functions.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included.

For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies to this document.

GB/T 2828.1 Sampling Procedures for Inspection by Attributes - Part 1: Sampling Schemes Retrieved by Acceptable Quality Limit (AQL) for Lot-by-Lot Inspection

GB/T 2829 Periodic inspection sampling procedures and tables (applicable to the inspection of process stability)

GB/T 4028 Inspection position markings for timing instruments

GB/T 17626.2 Electromagnetic compatibility testing and measurement techniques - Electrostatic discharge immunity test

3 Terms and Definitions

This document does not contain any terms or definitions that need to be defined.

4 Technical Requirements