Fluke 2470 User Manual

5-14 

 

gmq08.bmp 

When the piston is floating and rotating slowly (suspended on a gas cushion between 

piston stops) and not oscillating and the system is at equilibrium, and the Floating 

position of the piston is within +/- .06 inches (1.5 mm) of the Mid-float line on the 

column, a reading may be taken. To reduce the variability of the process, it is a “best 

practice” for the metrologist to take the reading at mid-float every time.   
The weights are to be rotated slowly by hand. The weights will rotate for sometime 

before they begin to slow. When the rotation of the weights comes to a stop, they can be 

rotated in the opposite direction. This allows the operator to observe any irregularities in 

the motion of the piston. For example, if the piston and weights begin to loose rotation 

speed very quickly, a dirty piston and cylinder is indicated. Chapter 6 of this manual, 

Piston/Cylinder Cleaning Instructions, includes detailed information for piston 

cleanliness checks.  
A thermometer well is provided on side of the gauge base opposite the pressure fitting. If 

a glass thermometer is preferred, one is provided with the base. Thermometer 

(P/N 99291-145-28-SB) is filled with a mercury-free temperature media.   
Pressure corrections for temperature, head height, Gravity, etc, are made according to the 

calculations and worksheets found in Appendix A. 

Performing the pressure correction calculations and documenting calibration data 

requires many redundant calculations and tedious recordkeeping. To facilitate this 

process and reduce the labor of these activities, the RUSKA 2456 Piston Gauge Monitor 

is a highly recommended. The RUSKA 2456 is equipped with a precision PRT (Platinum 

Resistance Thermometer) and electronic Float Position sensors.   
Pressure corrections for temperature, head height, Gravity, etc, are made according to the 

calculations and worksheets found in Appendix A. 
The RUSKA 2456 is provided with a copy of the RUSKA WinPrompt

®

 software. The 

RUSKA 2456 captures real time information for float position and P/C temperature and 

feeds this data into the RUSKA WinPrompt

®

 software (running on the customer’s 

computer). WinPrompt® automates all of the calculations performed on the Pressure 

Calculation worksheet noted in Appendix A.