PG1995
Active Member
Hi
I was just curious to find out that how a gas meter is read and how the total bill is calculated. The meter installed at home is Sensus CubixRS G4 (here is the **broken link removed**).
Q1:
Let's have a look on a picture of related gas meter below. (source)
i: If you see the specs of Sensus CubixRS G4, it says that cyclic volume is 1.20 dm3. It would mean that a cycle is completed for a flow of 1.20 dm3. Here, the cycle would mean that the right most disk on meter with the digits 0 through 9 moves from "0" to "0" to complete one cycle. Do you agree with me?
ii: I believe that the first three disks from the right shown between red outline use the unit of dm3. The rest of five disks use the unit of m3. There are 1000 dm3 in 1 m3. Do you agree?
iii: Suppose the meter reads 1000. Would you read it as 1 m3 or 1.2 m3? I would say that it should be read 1.2 m3 because the flow of 1.2 dm3 corresponds to one complete cycle therefore when 1000 cycles are completed, it would translate into 1200 dm3 or 1.2 m3. What do you say?
iv: The meter says that Pmax=75 mbar. I would interpret it to mean that maximum pressure of gas sustained by the meter is 75 mbar.
The figure of 75 mbar is too low. Standard atmosphere pressure is taken to be 101325 Pa or 1.01325 bar. Generally, two distinctions are made with given pressure. Pounds per square inch absolute (psia) is used to make it clear that the pressure is relative to a vacuum rather than the ambient atmospheric pressure. Since atmospheric pressure at sea level is around 14.7 psi, this will be added to any pressure reading made in air at sea level. The converse is pounds per square inch gauge or pounds per square inch gage (psig), indicating that the pressure is relative to atmospheric pressure. For example a bicycle tire pumped up to 65 psi above atmospheric pressure, will have a pressure of 65 + 14.7 = 79.7 psia or 65 psig.
I would say that the gas has higher pressure than the ambient atmospheric pressure therefore it's possible that Pmax should be read as "1.01325 bar + 75 mbar". What do you say?
Q2:
i: The unit used for billing is hm3 where 1 hm3 = 1000000 m3 (use this calculator for conversion). Last month we consumed 138 m3 as shown on the bill. A general thumb of rule to find hm3 is to divide number of cubic meters by 100 as I was told by a person who has worked for a gas company. So, 138 m3 would translate into 1.38 hm3. I don't even get how this rule of thumb for conversion works. Could you please help me?
ii: On the other hand, the bill didn't read 1.38 hm3 instead it was given 1.417 hm3. Now I don't even know how this number of 1.47 is calculated. But note that the bill does use some pres./factor and temp./factor where pres./factor=0.39/1.0266 and temp./factor is blank.
I do have some other questions but I believe that first I should clear the ones above. Thank you for your help.
Best wishes
PG
Helpful links:
1: https://en.wikipedia.org/wiki/Gas_meter
2: https://metricunitconversion.globefeed.com/Volume_Conversion.asp (extensive calculator for volume calculations)
I was just curious to find out that how a gas meter is read and how the total bill is calculated. The meter installed at home is Sensus CubixRS G4 (here is the **broken link removed**).
Q1:
Let's have a look on a picture of related gas meter below. (source)
i: If you see the specs of Sensus CubixRS G4, it says that cyclic volume is 1.20 dm3. It would mean that a cycle is completed for a flow of 1.20 dm3. Here, the cycle would mean that the right most disk on meter with the digits 0 through 9 moves from "0" to "0" to complete one cycle. Do you agree with me?
ii: I believe that the first three disks from the right shown between red outline use the unit of dm3. The rest of five disks use the unit of m3. There are 1000 dm3 in 1 m3. Do you agree?
iii: Suppose the meter reads 1000. Would you read it as 1 m3 or 1.2 m3? I would say that it should be read 1.2 m3 because the flow of 1.2 dm3 corresponds to one complete cycle therefore when 1000 cycles are completed, it would translate into 1200 dm3 or 1.2 m3. What do you say?
iv: The meter says that Pmax=75 mbar. I would interpret it to mean that maximum pressure of gas sustained by the meter is 75 mbar.
The figure of 75 mbar is too low. Standard atmosphere pressure is taken to be 101325 Pa or 1.01325 bar. Generally, two distinctions are made with given pressure. Pounds per square inch absolute (psia) is used to make it clear that the pressure is relative to a vacuum rather than the ambient atmospheric pressure. Since atmospheric pressure at sea level is around 14.7 psi, this will be added to any pressure reading made in air at sea level. The converse is pounds per square inch gauge or pounds per square inch gage (psig), indicating that the pressure is relative to atmospheric pressure. For example a bicycle tire pumped up to 65 psi above atmospheric pressure, will have a pressure of 65 + 14.7 = 79.7 psia or 65 psig.
I would say that the gas has higher pressure than the ambient atmospheric pressure therefore it's possible that Pmax should be read as "1.01325 bar + 75 mbar". What do you say?
Q2:
i: The unit used for billing is hm3 where 1 hm3 = 1000000 m3 (use this calculator for conversion). Last month we consumed 138 m3 as shown on the bill. A general thumb of rule to find hm3 is to divide number of cubic meters by 100 as I was told by a person who has worked for a gas company. So, 138 m3 would translate into 1.38 hm3. I don't even get how this rule of thumb for conversion works. Could you please help me?
ii: On the other hand, the bill didn't read 1.38 hm3 instead it was given 1.417 hm3. Now I don't even know how this number of 1.47 is calculated. But note that the bill does use some pres./factor and temp./factor where pres./factor=0.39/1.0266 and temp./factor is blank.
I do have some other questions but I believe that first I should clear the ones above. Thank you for your help.
Best wishes
PG
Helpful links:
1: https://en.wikipedia.org/wiki/Gas_meter
2: https://metricunitconversion.globefeed.com/Volume_Conversion.asp (extensive calculator for volume calculations)