SKF TMEH 1 User manual

SKF TMEH 1
OilCheck
Instructions for use

Table of contents Page
1. Introduction ........................... 3
1.1 Principle of operation ..................... 3
2. Technical data ......................... 3
3. Operating instructions ..................... 4
3.1 Calibration .......................... 4
3.2 Sensor cleaning ....................... 4
3.3 Measuring .......................... 5
3.4 Interpretation of the reading ................. 5
4. Contamination effects ..................... 6
5. Important information ..................... 7
6. Maintenance ........................... 7
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1. Introduction
The SKF OilCheck TMEH 1 measures the effect of contamination and
electro-chemical changes that occur in synthetic and petroleum based
oils. It is especially developed for engine oils but is also suitable for gear
and lubrication oils.
The OilCheck is a portable instrument which offers a two-minute
alternative to lengthy laboratory investigations.
1.1 Principle of operation
The OilCheck detects and measures the dielectric constant of an oil.
By comparing the measurements obtained from used and unused oils of
the same brand, the SKF OilCheck is able to determine the degree of
change in the dielectric constant of the oil. Dielectric change is directly
related to the degradation and contamination level of the oil and helps
the user to optimise intervals between oil changes and to detect
increased mechanical wear and loss of the oils lubricating properties.
To facilitate trending the instrument is equipped with a numerical
read-out.
2. Technical data
CE requirements : all applicable norms fulfilled.
Suitable oil types : Mineral and synthetic oils
Repeatability : Better than 5%
Read-out : Green/Red grading + Numerical value
(0 -100)
Battery : 9 V Alkaline, IEC 6LR61
Battery lifetime : 150 hours or 3.000 tests
Dimensions (instrument) : 250 x 95 x 32 mm (9,8 x 3,7 x 1,3 in)
Designation : TMEH 1
Sample sensor
Re Cal button
Display
Test button
ON/OFF
HI/LO switch
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3. Operating instructions
3.1 Calibration
Before calibration it is important to
ensure the sensing cell is clean and dry,
as moisture and contamination will
adversely effect the results.
Testing should generally be undertaken
with the unit switched in the HI position.
The Green/Red scale is mainly for use
when testing engine oils.
Step 1.
Half fill the sensing cell with clean oil
(ensure that the whole surface of the
sensor is well covered with oil). Oil of the
same brand as in the system being
evaluated, should be used for calibration.
Step 2.
Run the rotary switch from the OFF
position to the HI position, the display will
complete a full sweep and return to the
zero position. The display will show with
the CAL symbol flashing. If during testing
the CAL graphic flashes the unit will
require re-calibration.
Step 3.
Press the test button. The CAL graphic
will disappear and one segment will
remain displayed. The instrument has
now calibrated itself against the clean
sample and is ready to test the oil in your
system.
Note: Ensure that the CAL knob is not
pressed as this will put the instrument
back into calibration mode and the unit
will need to be re-calibrated.
3.2 Cleaning of sensor
Remove the unused sample from the
sensor cell with a clean rag or tissue.
Clean the sensor by using an
electro-contact cleaning solution
(penetrating, fast-evaporating,
non-residue solution).
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3.3 Measuring
For optimum results make sure you use
a representative oil sample and that its
temperature is not higher than 40°C
(100°F). Place enough oil in the sensor
to fully cover the sensor surface. Press
the test button and keep it depressed for
10 seconds or until the segments have
stopped moving around the display
(the display will flash to show the unit is
testing). The result will remain on the
display when the button is released until
the next test is carried out.
To test again, clean out the sensor well
with a clean rag or tissue. Refill the
sensor well and press the test button
again. A new reading will appear on the
display.
In case an oil of another brand is
checked, re-calibration of the instrument
will be needed.
3.4 Interpretation of the reading
Users should use the OilCheck to
monitor the change in the oils properties
and build up a picture of oil degradation
based on their experience and own
operating criteria. Individual thresholds
of acceptability can be marked on the
unit’s scale.
The red and green areas are designed
as an indicator of the condition of an
engine oil. Within the green band the oil
is deemed acceptable and within the red
area the oil should be changed and
checked again after a short running
period to ensure no mechanical
problems are present.
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4. Contamination effects
The usual contamination found in oils is caused by oxidation and acid
build up, these occur during the normal running of an engine and should
show up as a gradual increase in readings over a period of time or
distance.
Other contaminants occur because of excessive wear or mechanical
failure, the main elements of which are dirt, soot, fuel, water, anti-freeze
and metal particles.
These elements give a marked increase in the OilCheck’s reading and
will give immediate warning of possible resulting failure.
1. Water and anti-freeze contamination will cause a dramatic change in
the reading which will move the segments well into the red.
2. Metal particles will also cause an extreme reading though the display
should move up in small jumps as the particles settle on the sensor
surface.
3. Fuel is harder to detect as its presence will sometimes mask the
presence of other contaminants. If the oil is only contaminated by
fuel the display will show it as a stronger reading well into the red but
the presence of water or metal will sometimes counteract the fuel
giving a reading in the green. Should an engine oil continue to show
no increase in its reading over a period of time the possibility of fuel
contamination should be investigated.
4. Changes in the viscosity of the oil will cause a slow reduction of the
dielectric constant which will be difficult to detect.
5. Changes of the acidity will typically reduce the dielectric strength in a
detectable manner.
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5. Important information
For the best results please ensure these guidelines are adhered to:
1. The OilCheck is very sensitive to moisture. Ensure that the surface
of the sensor is dry and that the unit is not used in conditions of high
humidity, snow, rain or fog.
2. Extremes of temperature will also affect the results, ensure that the
unit is calibrated at the ambient temperature at which the tests will be
conducted. Normal operating temperature is between 5°C - 25°C.
3. Ensure that the sample taken from the engine does not pick up
contamination from airborne particles or moisture. Use a vacuum
sampler if available.
4. Treat the surface of the sensor with care as excessive scratching
and abrasion of the tracks will damage the product.
5. The unit can not be used for fire resistant fluids
(water-in-oil-emulsion).
6. Maintenance
Keep the instrument clean and do not allow the instrument to get wet.
If the instrument is dropped or hit the device should be re-calibrated to
re-check its performance.
To replace the battery remove the 2 screws holding the battery cover in
place.
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In line with our policy of continuous development of
our products we reserve the right to alter any part of the
above specification without prior notice.
Although care has been taken to ensure the accuracy of
this publication, SKF does not assume any liability for errors
or omissions.
SKF Maintenance Products
© Copyright SKF 2001/08 www.mapro.skf.com
MP504E