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Copper corrosion bath · Calibration procedure

Bath temperature check

Checks that the copper strip corrosion bath holds the test temperature (for example 50 °C and 100 °C) within about ±1 °C at the positions used.

Illustration of Copper corrosion bath
PURPOSE

Why this is checked

Copper corrosion results depend on temperature as well as time. ASTM D130 requires the bath to be held at the test temperature within about ±1 °C. This check confirms the bath meets that across the positions where tubes or pressure vessels sit.

Frequency

Typically a reading at each use, and a multi-position check every 6–12 months or per SOP.

Learn how the Copper corrosion bath works
YOU WILL NEED

Standards & tools

  • Calibrated reference thermometer or probe traceable to national standards
BEFORE YOU START

Prerequisites

  • Bath at the set temperature for at least 30 minutes
  • Medium level correct
  • Reference thermometer in date
PROCEDURE

Step by step

  1. 1Place the reference thermometer in a test tube of oil (or the medium) at the first position, at the depth of the strip.
  2. 2Record the stable reading.
  3. 3Repeat at each position used.
  4. 4Repeat at each test temperature (for example 50 °C and 100 °C).
  5. 5Calculate deviation from set temperature at each position.
RECORD

Example observation table

PositionSet (°C)Reference reading (°C)Deviation (°C)
15050.3+0.3
25049.8−0.2
35050.1+0.1
45050.4+0.4
CALCULATION

How to calculate the result

Formula
Deviation = reading − set temperature
Worked example
  1. 1

    Deviations: +0.3, −0.2, +0.1 and +0.4 °C.

  2. 2
    Mean = (50.3 + 49.8 + 50.1 + 50.4) ÷ 4 = 50.15 °C; spread = 50.4 − 49.8 = 0.6 °C.
  3. 3

    Largest deviation 0.4 °C is within ±1 °C — pass.

ACCEPTANCE CRITERIA

Pass if

  • All positions within ±1 °C of the test temperature (or the limit in the current method and your SOP).
IF IT FAILS

What to do

  • Check medium level, stirring and lid; adjust controller and repeat.
  • Withdraw failing positions or the bath from use until repaired.
  • Assess copper corrosion results since the last good check.
In LimsPulse · Calibration Management

LimsPulse schedules this calibration, records the result against limits, and blocks the instrument everywhere if it fails or goes overdue.

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