a practical alternative to karl fischer titration for ... practical alternative to... · a...

© 2014 Spectro Scientific | CONFIDENTIAL

FEBRUARY 2015

1

A Practical Alternative to

Karl Fischer Titration for Water

Measurement in Lubricating Oils


Overview

FluidScan provides

quantitative measurement

of dissolved water, based

upon IR absorbance.

This capability has been

extended and now

measures free water.

2


Water Limits – Industry Best Practices

Recommended water limits for machinery oils are

below saturation levels (dissolved water)

– Typical moisture levels are specified below (ppm)

• Hydraulics 125

• Gearboxes 300

• Paper machines 200

• Steam turbine 100

• Pumps 150

In real world applications, however, free water is

frequently present (water above saturation limit)

The FluidScan Comprehensive Water Solution

measures dissolved and free water.

3


Principle of operation (patent pending)

Free water droplets scatter

IR light, in proportion to the

amount of free water present,

resulting in a vertical shift of

the IR absorbance curves, or

‘baseline shift’.

Extensive Applications

development has quantified

correlations between the

FluidScan baseline shift and

Karl Fischer titration values.

4

Comprehensive Water Solution Extended Range


Measurement Range of FluidScan

5


No Detectable Free Water Detects Free Water

Display of Measured Results

6

• Displayed value shows high

Oxidation and TAN, but no free

water.

Displayed value is sum of

dissolved water + free water

Note: Saturation Limit of GST46 <400 ppm


Oil Categories Covered by Extended Water

Range Algorithm

7

Oil Category Extended Water Range

Chiller

Compressor

Gear-splash

Gear-pressure

Hydraulic

Transmission

Turbine Aero

Turbine Steam, CCGT

Engine N/A


Correlation to Karl Fischer

Plot of 65 samples from

twelve different oil

categories

Correlation to Karl Fischer

Titration = 95.7%

Specified sample

preparation technique

provides good repeatability

8


Sample Preparation Sample preparation is

key to obtaining good

results

If water droplets are not

evenly dispersed in the

oil sample, this can give

misleading results

Homogenizing the

sample gives uniform

and repeatable results

9


Sample Preparation Homogenize sample for 30 seconds

Wait at least 1 minute

Invert bottle 20 times gently

Draw a sample from the center of the bottle

Test with FluidScan

10

Homogenized samples

Water separated from oil sample

Benchtop homogenizer


Requirement for Homogenizer

Must adequately homogenize

sample for meaningful

measurement

Two homogenizer options:

– Table top with stand

– Portable, rechargeable

11


Summary

The Comprehensive Water Solution combines a simple sample

preparation technique and an extended water range library on the

FluidScan to provide a Practical Alternative to Karl Fischer

titration.

The FluidScan is a handheld device that offers a practical solution

for maintaining the key parameters of a healthy lubrication system

without the need for a laboratory. Key measurement parameters

include:

– Water (dissolved and free)

– TAN (total acid number)

– Oxidation

12

a practical alternative to karl fischer titration for ... practical alternative to... · a...

Documents