Volumetric Apparatus and Densimeter in non liquid usage type composes of cylinder which is in shape of tube for filling in by the object needed to be measured with inside pushing support stick for supporting the moving forth-back of pushing stick to transmit the pressure force to make pushing support stick moving forth-back to be able to move forth-back. The moving forth-back of said pushing support stick is to measure the distance of the moving forth-back compared with original distance by send-receive signal transmitter equipped outside cylinder. The cylinder is separated into two parts of which each part supports for in-out pressure by inside pushing stick that push in-pull out by external force to measure the object needed to be measured placed at one part of cylinder that separated to measure the moving forth-back of inside pushing stick by distance meter unit at least two units. Then, the units calculates the changed distances in cylinder as data for finding volume and density and air pressure inside cylinder at least one cylinder and to be sent to pressure and vacuum meter and displays in numbers or signs to show pressure inside cylinder as support data in calculation of volume and density of the object needed to be measured.

The method can determine a density of concrete based on the measured buoyancy of a buoy immersed in fresh concrete contained in a ready mix drum and rotatable therein as the drum is rotated, the method can include obtaining a first measurement of a force applied to the buoy while the buoy is being moved tangentially in the fresh concrete, obtaining a second measurement of a force applied to the buoy while the buoy is being moved tangentially in the fresh concrete by rotation of the cylindrical wall, obtaining an indication of the buoyancy of the buoy in the concrete including factoring out the yield effect based on at least the first measurement and the second measurement.

Volumetric Apparatus and Densimeter in non liquid usage type composes of cylinder which is in shape of tube for filling in by the object needed to be measured with inside pushing support stick for supporting the moving forth-back of pushing stick to transmit the pressure force to make pushing support stick moving forth-back to be able to move forth-back. The moving forth-back of said pushing support stick is to measure the distance of the moving forth-back compared with original distance by send-receive signal transmitter equipped outside cylinder. The cylinder is separated into two parts of which each part supports for in-out pressure by inside pushing stick that push in-pull out by external force to measure the object needed to be measured placed at one part of cylinder that separated to measure the moving forth-back of inside pushing stick by distance meter unit at least two units. Then, the units calculates the changed distances in cylinder as data for finding volume and density and air pressure inside cylinder at least one cylinder and to be sent to pressure and vacuum meter and displays in numbers or signs to show pressure inside cylinder as support data in calculation of volume and density of the object needed to be measured.

In order to mechanically monitor a gas density of a greenhouse gas in a more climate-friendly and cost-effective manner, the invention provides a density monitoring method for monitoring the gas density of a noxious gas (10), comprising: a) providing a closed reference volume (26) with a partition wall (28) movably disposed between the reference volume (26) and the noxious gas (10) to be monitored, b) providing a reference gas (56) which has a lower global warming potential relative to the noxious gas (10) by at least a factor of two in the reference volume (26) at a reference gas pressure which is higher than the filling pressure of the noxious gas (10), c) compensating, by means of a spring device (32), for a force acting on the separation wall (28) due to the increased reference gas pressure in the reference volume (26), and d) detecting a deflection of the partition wall (28) for monitoring the gas density. A gas density monitor (14), its use in such a method and an electrical system provided therewith are also proposed.