Fluke RUSKA 2470 User Manual

 

6-1 

When it is necessary to clean the Piston/Cylinder Assembly, the Piston Pressure Gauge 

must be partially disassembled and some of the components set aside until later. Upon 

removal of the internal components, a degree of risk is involved because of the possibility 

of exposing the parts to harmful dirt, corrosive fingerprints, and being dropped to the 

table or floor. The small, carbide measuring piston will not likely survive an accidental 

drop. The remainder of the components, if dropped, may also be damaged to the extent of 

sustaining raised burrs and may no longer be useable. 
Each manual operation that is performed on a mechanical device is accompanied by a 

finite degree of damage. The damage, however small it may be for the individual 

operations, is cumulative. It results from the imperfect execution of each manual 

operation. After a given length of time, the device may be expected to fail because of 

performance deterioration beyond the level of tolerance. It is important, therefore, to 

perform the manual operations with the greatest possible skill in order to keep the 

harmful side effects at a minimum. 
There are two types of contamination that affect not only the performance of a piston 

pressure gauge but also the mechanical state of the critical components. One contaminant 

is the ordinary hard particle of matter that scratches and abrades the finely-finished 

surfaces as it becomes entrapped between the close-fitting members. The scratches 

invariably result in raised edges from the displacement of the metal and spoil the original 

relationship of the members. The second type of contaminant is of a chemical nature and 

produces harmful effects by attacking the finished metallic surfaces in a corrosive manner. 

Ordinary fingerprints contain water-soluble, acidic salts, having extremely high corrosive 

activity with the metals of the critical instrument parts. Since these parts must necessarily 

be handled in making a piston exchange, they may be protected from exposure to both 

types of contaminants by the use of clean paper wipers.  
There are a number of industrial paper wipers such as Kimwipes available that are 

relatively free of lint. After a little practice, the corrosion-sensitive parts may be safely 

handled with these wipers instead of with the bare fingers. Even when using the wipers as 

insulators, the hands should first be washed and thoroughly dried before beginning the 

disassembly.  
The space allotted to the discussion of cleanliness is not intended to imply to the 

technician the impossibility of performing the job correctly, but rather to give him 

reassurance that the results will be quite satisfactory if he follows common-sense 

procedures of eliminating contaminations by use of proper techniques.