ASTM D1279-82(1994)

I - 0759510 0543243 79T m
Designation:D 1279 - 82(Reapproved 1994)
Standard Test Method for
Buffering Action of Metal Cleaners’
This standard is issued under the fixed designation D 1279; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number m parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an titorial change since the last revision or reapproval.
1. Scope 1 pH unit or some definite change in pH, as agreed upon
between the seller and the purchaser. Examples of change in
1 .l This test method covers the determination of the
pH ranges are as follows:
buffering action of metal cleaners.
4.1.3.1 From initial pH of a solution to pH of 12.0,
1.2 This standard does not purport to address all of the
4.1.3.2 From pH 12.0 (or initial pH if between 11 and 12)
safety concerns, if any, associated with its use. It is the
down to pH 11 .O, and
responsibility of the user of this standard to establish appro-
4.1.3.3 From pH 11.0 down to pH 10.0.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
5. Procedure
5.1 Prepare 500 mL of a solution of 3.75 g (1 o&al) of
2. Referenced Document
the cleaner in distilled water.
2.1 ASTM Standard:
5.2 Transfer 100 mL of the solution at 25 f 1°C to a
E 70 Test Method for pH of Aqueous Solutions with the
400-mL beaker.
Glass Electrode2
5.3 Determine the initial pH in accordance with Test
Method E 70, using the high pH (low-sodium-error) elec-
3. Significance and Use
trode.
3.1 This test method is used to compare the buffering
5.4 Add 1 .O-mL increments of 0.5 N HCl to the solution.
capacity of alkaline metal cleaners in terms of a buffer index,
Bring the solution to equilibrium after each acid addition,
that is, the volume of standard acid needed to obtain a
and record the pH. Add further l.O-mL increments of 0.5 N
specified pH reduction. The users will define the buffer
HCl, and record the corresponding pH values. Terminate the
index.
additions of HCl at a pH of 9.
4. Terminology 6. Calculation
4.1 Dejinit
...