GB/T 22778-2021Liquid crystal digital quartz stopwatches (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for Standardization Work Part

1.Structure and Drafting Rules of Standardization Documents" Drafting. This document replaces GB/T 22778-2008 "LCD Digital Quartz Stopwatch", compared with GB/T 22778-2008, except for editorial changes The main technical changes outside the move are as follows:

---Modified the "normative references" (see Chapter 2, Chapter 2 of the.2008 edition);

---Revised the "period measurement accuracy" (see Table 2, Table 6,.2008 Edition of Table 2, Table 6);

---Modified the "temperature coefficient" (see Table 3, Table 3 of the.2008 edition);

--- Deleted the requirements and test methods of "humidity resistance" related to low temperature and humidity resistance (see 5.8, 6.4.8,.2008 edition of 4.8, 5.4.8);

--- Modify the requirements and test methods of "light resistance performance" to the requirements and test methods of "light performance" (see 5.14, 6.4.14, (2008 version 4.14, 5.4.14);

--- Added "Additional Functions" (see 5.17, 6.4.17, Appendix A);

---Modified the "test environment" (see 6.1.1,

5.1.1 of the.2008 edition);

---Modified the "test equipment" (see Table 5, Table 5 of the.2008 edition);

---Modified the test method of "button fatigue resistance" (see 6.4.13,.2008 edition of 5.4.13);

---In the "factory inspection", an inspection of waterproof performance has been added (see Table 8, Table 8 of the.2008 edition);

--- Modified the markings in "Dial surface and back cover" (see 8.1.1,

1 Scope

GB/T 22778-2021 is the Chinese national standard on liquid crystal digital quartz stopwatches, in the field of precision mechanics and jewellery. The /T suffix marks it as a recommended standard: it is not compulsory by itself, but it becomes binding as soon as a contract, a tender or a customer specification calls it up - which in practice is how most foreign buyers meet it. It was issued on 20 August 2021 by the State Administration for Market Regulation; Standardization Administration of China, and has been in force since 1 March 2022. Classification: ICS 39.040.10, CCS Y11. This page is published from the official record of the standard held by the Chinese standards administration: the identification, the dates, the classification and the issuing body are taken from there. The clause text, the tables and the numeric limits are in the document itself, which is delivered complete in English translation.

2 Normative references

The contents of the following documents constitute the indispensable clauses of this document through normative references in the text. Among them, dated quotations Only the version corresponding to that date is applicable to this document; for undated reference documents, the latest version (including all amendments) is applicable to this document.

GB/T 2828.1 Sampling inspection procedure by attributes Part

GB/T 2829 Periodic Inspection Sampling Procedures and Tables by Attributes (Applicable to the Inspection of Process Stability)

GB/T 17626.2 Electromagnetic compatibility test and measurement technology Electrostatic discharge immunity test

GB/T 30106 Waterproof watches

GB/T 38022 Anti-shock watches for clocks

3 Terms and definitions

There are no terms and definitions that need to be defined in this document.

4 Categories

Quartz stopwatches are divided into dedicated type and non-dedicated type according to their purpose. See Table 1 for specific classification. Table

1 Classification Stopwatch type resolution usage Dedicated full-time 0.01s handheld Non-dedicated part time 0.01s handheld or wrist

5 Requirements

5.1 Working temperature The functions and LCD display of the special quartz stopwatch should be complete and normal at -5°C~50°C. The functions and LCD display of the non-dedicated quartz stopwatch should be complete and normal within 0°C~50°C.