Difference between revisions of "T08 Sprayability Test Rig"

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(Created page with 'The Mettler Mass Comparator in the Tribology Lab The Mettler Coparator Balance is not a normal mass meter. It is used for measur...')
 
(→‎Test Procedure)
 
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[[File:Mettler_%282010%29.JPG|500px|right|thumb|The Mettler Mass Comparator in the Tribology Lab]]
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[[File:Sprayability.JPG|400px|right|thumb|The sprayability rig in the Tribology Lab]]
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The Mettler Coparator Balance is not a normal mass meter. It is used for measuring very small changes in mass AND SHOULD ONLY BE USED TO MEASURE THE FZG GEARS BEFORE AND AFTER TESTS.
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== Documentation ==
 
== Documentation ==
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Mettler Mass Comparator User Manual is available [ftp://anonymous@ragnarok.up.ac.za/publicftp/lab/Tribology/Mettler%20Mass%20Comparator/User%20Manual%20%28Mettler%29.pdf here]. Please read the manual before using the instrument.
 
  
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== Time Line ==
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== Test Procedure ==
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Comparator fixed by Mettler and returned on 27 June 2010.
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== User Tips ==
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Download the [ftp://anonymous@ragnarok.up.ac.za/publicftp/lab/Tribology/Sprayability%20Test%20Rig/BE%40UP%20Tribology%20lab%20Test%20Descriptions%28Sprayability%29.pdf Grease Sprayability Test Procedure]
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When starting the instrument in the morning, place a weight of known mass onto the scale and take the reading. Write the value down. If this value deviates too much from the original value (the value on the day of calibration), contact the Mettler people to re-calibrate the machine. The following weights were measured on 04 June 2010:
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* Gerrie's 2 kg weight = 1999.820 g
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* Gerrie's 1 kg weight = 1000.141 g
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Another useful tip is to move the weight around on the surface of the scale when you make your first reading. This ensures that the whole surface is "activated" and ensures better accuracy.
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The sprayability test rig consists of the following elements:
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* A single-plunger grease pump, type Delimon FZ-B;
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* A standard Delimon type FZ-B progressive lubricant distributor serving 6 120° flat spray nozzles;
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* A logic circuit controlling the timing sequence of the spray system; and
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* An air pressure regulator.
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The nozzles are spaced equidistant at 160 mm intervals so as to ensure no overlap between spray patterns of individual nozzles. The nozzles spray against a sheet of clear Mylar which is placed perpendicular to the spray direction and at a distance of 150 mm from the nozzles. Four complete spray bursts of 7 seconds duration each are collected on the Mylar sheet, after which the sheet is removed and photographed. (In most cases only one spray burst is necessary).
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Each spraying cycle delivers 0,2 cubic centimeters of lubricant per nozzle. The delivery air pressure is maintained at 200, 300 and 500 kPa. The test is performed at ambient temperature.
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A modified spray test is also performed at below ambient temperatures. The test is conducted in the following manner:
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A grease gun is filled with the grease to be tested and placed in a refrigerator to reach the required temperature: -5 or 0°C. The grease gun is attached to the distribution block of the Delimon apparatus described above. The same number of bursts is sprayed onto a Mylar sheet through one spray nozzle
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Visual analysis of the spray pattern leads to a grading on a scale of 1 to 5:
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# Excellent
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# Very good
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# Acceptable
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# Below average
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# Poor
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The properties evaluated are: Spray pattern, Area coverage of lubricant, Distribution of particles, Form of particles, Size of sprayed particles.

Latest revision as of 15:53, 26 July 2010

The sprayability rig in the Tribology Lab

Documentation

Test Procedure

Download the Grease Sprayability Test Procedure

The sprayability test rig consists of the following elements:

  • A single-plunger grease pump, type Delimon FZ-B;
  • A standard Delimon type FZ-B progressive lubricant distributor serving 6 120° flat spray nozzles;
  • A logic circuit controlling the timing sequence of the spray system; and
  • An air pressure regulator.

The nozzles are spaced equidistant at 160 mm intervals so as to ensure no overlap between spray patterns of individual nozzles. The nozzles spray against a sheet of clear Mylar which is placed perpendicular to the spray direction and at a distance of 150 mm from the nozzles. Four complete spray bursts of 7 seconds duration each are collected on the Mylar sheet, after which the sheet is removed and photographed. (In most cases only one spray burst is necessary).

Each spraying cycle delivers 0,2 cubic centimeters of lubricant per nozzle. The delivery air pressure is maintained at 200, 300 and 500 kPa. The test is performed at ambient temperature.

A modified spray test is also performed at below ambient temperatures. The test is conducted in the following manner:

A grease gun is filled with the grease to be tested and placed in a refrigerator to reach the required temperature: -5 or 0°C. The grease gun is attached to the distribution block of the Delimon apparatus described above. The same number of bursts is sprayed onto a Mylar sheet through one spray nozzle

Visual analysis of the spray pattern leads to a grading on a scale of 1 to 5:

  1. Excellent
  2. Very good
  3. Acceptable
  4. Below average
  5. Poor

The properties evaluated are: Spray pattern, Area coverage of lubricant, Distribution of particles, Form of particles, Size of sprayed particles.

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