---
title: "ASTM D3634"
url: "https://mat-cs.com/astm-d3634/"
description: "This test method covers the determination of chloride ion in engine coolants in the range from 5 ppm to 200 ppm in the presence of up to 0.6 weight % mercaptobenzothiazole."
---

ASTM Standard

# ASTM D3634

Standard Test Method for Trace Chloride Ion in Engine Coolants

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## Significance and Use

4.1 This test method permits the determination of very low levels of chloride ion in engine coolants containing the common corrosion inhibitor, mercaptobenzothiazole, or related mercaptans, which would normally interfere with the titration by also forming insoluble silver salts with silver nitrate.

## Scope

1.1 This test method covers the determination of chloride ion in engine coolants in the range from 5 ppm to 200 ppm in the presence of up to 0.6 weight % mercaptobenzothiazole.

1.2 Other materials that react with silver ion will interfere.

1.3 Chloride in engine coolants containing an aryltriazole instead of mercaptobenzothiazole can be determined directly by this test method without pretreatment with hydrogen peroxide.

1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.