In order to periodically check the LPG meters supplied with LPG vehicle refuelling road-side distributors, we need to have a “sample bottle” or “special double decalitre”, which is manufactured by us.
This particular instrument, which possesses the requirements of 3 Ministerial Decrees of the Italian Ministry of Industry, is used to check the quantity supplied by the LPG meter with the greatest possible precision, and allows LPG meters to be calibrated to the tolerances set by the Metric Office – under the Market Protection Service of the Chamber of Commerce – to within ± 0,5% (± 5%).


The LPG is measured through the 20 l sample bottle with a visual field of ±0,5 l and reading every 0.2 dl subdivision of the scale.
The measurement is based on the principle of evaluating the capacity as if the liquid inside was at the same vapour tension as water.
This is obtained by connecting the closed cycle of the sample bottle to the tank from where the LPG used for measuring is taken.
If there are no modifications to the vapour tension of the product in the bottle compared to that in the tank, the measured value is exactly the same as the one delivered.

                  
Calibration kit LPG meters:
• special double decalitre
• dedicated LPG compressor unit for bottle emptying after
   every single test
• piping set (2x5 m compressor suction and draining gas phase   + 1x3 m bottle draining liquid phase)
• standard Italy pistol for connecting to bottle
  (to be installed on the compressor draining piping)