pH Measurement of Leather

The REX PH300F pH Meter allows quick and simple determinations of the pH of leather with 0.01 pH accuracy and timed-reading by setting within 30 s to 60 s.

Leather technicians rely on a pH determination to optimize dyes, coating, and softening agents in order to preserve the fiber structure and prevent damage to leather. Leather is acidic.

The pH requirements of leather and leather leather for clothing standards are 3.2 ~ 6.0, and the pH requirements of leather clothing and fleece-filled leather clothing standards are ≥3.5. All fur (wool fur, rabbit fur, goat hair, fox fur, mink fur, raccoon fur) leather clothing, fur clothing standards for fur pH requirements of 3.8 ~ 6.5, fur standard for fur pH requirements of 4.0 ~ 6.5.

1.Standard Reference

BS EN ISO 4045-2018 Leather -Chemical tests -Determination of pH and difference figure

2.The Principle

This document specifies a method for determining the pH value and the difference figure of an aqueous leather extract. It is applicable to all types of leather.

Preparation of an aqueous extract from a test portion of the leather and measurement of the pH of the extract, using a pH meter. In cases where the pH value obtained is below 4,00 or above 10,00, the pH value of a tenfold dilution of the aqueous extract is also determine

3.Recommended Configuration

PH300F pH meter

The pH meter, with glass electrode, with a measuring range of 0 pH units to 14 pH units, graduated in 0,01 pH units.

Determination of the pH value

Ensure that the extract (8.1) is at (20 + 2)°c. lmmediately after stirring, immerse the electrode in the extract solution and determine the pH value with the pH meter (6.2), to the nearest 0,05 pH unit, as soon as a steady reading has been reached. The reading should be taken within 30 s to 60 s.

 

• pH Accuracy meets ±0.01 pH.
• Multi-reading feature allows auto-read, timed-read and continuous-read. 
• Automatic/Manual temperature compensation ensures accurate results.
• Automatic electrode diagnosis with pH slope and offset display.

 

pH Electrodes

Aqueous extracts of heavily fat-liquored leather may in time make the electrode membrane dirty. In such cases, the membrane shall be lightly rubbed with a piece of cotton wool dipped in acetone or the electrode should be suspended in a 1:1 water:acetone mixture. After cleaning, the membrane should again be thoroughly soaked in water.

 

65-1C pH composite electrode

  According to the cleaning procedure, the electrode may be immersed in the acetone, so it needs a glass body.

Model	65-1C
Name	pH composite electrode
pH Range	0～14
Fill Solution	3 M KCl
Sensor material	Glass
Working Temp.	5~60 ℃
Junction material	Single ceramic
Reference Type	Ag/AgCl
Dimensions	Φ12×120 mm
Connector Type	BNC(Q9)

 

962242 pH composite electrode (Flat )

 

Flat pH measurements provide a non-destructive means to meet specifications and optimize product quality.

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Model	962242
Name	pH composite electrode (Flat )
pH Range	1～12
Fill Solution	3 M KCl
Sensor material	Glass
Working Temp.	0~60 ℃
Junction material	Unmovable glass grinding mouth
Reference Type	Longlife Ref.
Dimensions	Φ12×120 mm
Connector Type	S7