Fluke RUSKA 2470 User Manual

3-1 

The RUSKA Gas Lubricated Piston Pressure Gauge, model 2470 is a pneumatic pressure 

standard designed for the accurate generation and measurement of gas pressures to 

3000 psig. This measurement is accomplished in the basic manner of using the 

fundamental pressure equation PRESSURE = FORCE/AREA (see Chapter 2, General 

Piston Pressure Gauge Considerations, for more information). The gauge is used as the 

precision measuring device in the RUSKA Gas Lubricated Piston Pressure Gauge System. 
It may be seen from the above general equation that when a known force produced by a 

known mass is applied to a piston of a known area, a pressure will be produced that may 

be calculated (see Appendix A for detailed information). The RUSKA gauge is arranged 

for the application of carefully determined masses on a piston of known area. 
A key feature of the gauge is its ability to accurately reproduce its performance at the 

lower pressures. The low viscosity of the gas provides excellent lubrication for the 

close-fitting piston/cylinder assembly. Relative motion between the piston and cylinder is 

necessary and is obtained by hand rotation of the masses and table which will then 

distribute the gas molecules throughout the annulus of the assembly. It is the relative 

absence of friction between piston and cylinder walls that characterizes the performance 

for which the gauge is so highly respected.   
The nominal range of pressure (interval) over which the gauge is capable of operating is 

the span from 1.4 kPa (0.2 psig) to 20.6 MPa (3000 psig). This interval is covered by 

three interchangeable piston/cylinder assemblies having sufficient overlap for 

establishing continuity of measurement and for making detailed investigations of 

subintervals within the total range (span). 
Some of the most important industrial uses of the gas lubricated piston pressure gauge is 

that of a standard for calibrating transducers, Bourdon-tube type gauges, manometers, 

and other dead weight gauges. Frequently, the gauge is used in combination with the 

pressure null transducer (RUSKA model 2413 or similar) for cross float calibrations 

between gaseous and hydraulic media.