7 replies to this topic

[rsk]

Sir I have tyre in atmosphere with PG connected to its filling nozzle. It reads 2kg/cm2 gauge. If I take this to a pressurised chamber of 3kg/cm2 gauge, what the PG connected to tyre will read?

[rsk]

Its bourdon type gauge.

[Saml]

It will read "vacuum". Bourdon measures "gauge" pressure, that is, relative to the surroundings. 

[fallah]

 If I take this to a pressurised chamber of 3kg/cm2 gauge, what the PG connected to tyre will read?

 

rsk,

 

It should show 3kg/cm2g, provided that this value is being among PG measuring range....
 

[rsk]

If I take this to a pressurised chamber of 3kg/cm2 gauge, what the PG connected to tyre will read?

rsk,

It should show 3kg/cm2g, provided that this value is being among PG measuring range....

[rsk]

Sir
tyre is getting pressurised to 5 kg/cm2, due to internal pressure of 2 kg/cm2 and external chamber's pressure of 3kg /cm2. But same 3kg /cm2 is also acting outside of PG bourbon tube. I think it should read 2kg/cm2 only as earlier. Please clarify.

[fallah]

Sir
tyre is getting pressurised to 5 kg/cm2, due to internal pressure of 2 kg/cm2 and external chamber's pressure of 3kg /cm2. But same 3kg /cm2 is also acting outside of PG bourbon tube. I think it should read 2kg/cm2 only as earlier. Please clarify.

 

rsk,

 

Your descriptions are confusing...a simple sketch might help to understand the actual matter...

 

Anyway, appears the PG would show vacuum equal to 1kg/cm2 ...

[Pilesar]

Simplifying assumption: tire volume is constant. Convert the pressures to absolute pressure to make computation easier. Outside the pressurized chamber, the tire has internal pressure of 3 kg/cm2(abs). The external pressure is 1 kg/cm2(abs). Pressure gauge measures the difference and shows internal pressure of 2 kg/cm(g). Then move the tire into the pressurized chamber. The tire has internal pressure of 3 kg/cm2(abs). The external pressure is 4 kg/cm2(abs). The pressure gauge measures the difference and shows -1 kg/cm2(g).