# Volume of resp. Chamber

**StefanM**(@stefanm)3 Posts

Quote from StefanM on August 31, 2018, 2:00 pmHi,

according to the documentation, the input.info function needs the "chamber volume" as arguments. I take that the volume of the whole respirometry loop is meant. Still, I wonder, if the function calculates the effective volume by itself as in:

Volume(effective) = Volume(total) - Mass(fish)

Or should I insert the effective volume?

Best,

Stefan

Hi,

according to the documentation, the input.info function needs the "chamber volume" as arguments. I take that the volume of the whole respirometry loop is meant. Still, I wonder, if the function calculates the effective volume by itself as in:

Volume(effective) = Volume(total) - Mass(fish)

Or should I insert the effective volume?

Best,

Stefan

**Sergey Morozov**(@samoedd)9 Posts

Quote from Sergey Morozov on September 2, 2018, 10:58 amHi Stefan,

The argument "chamber volume" can be used for both the volume of chamber and the volume of the whole respirometry. Basically, "chamber volume" is the total volume of the respirometry loop.

Thank you for this note, I will clarify this moment in the documentation of the R package.

Yes, it calculates the effective volume as you described in the function calculate.MR. The calculation of absolute metabolic rate is based on the following equation:

absMO_{2}=Δ[O(_{2}]/Δt ×)V – D × mwhere,

s Volume of a chamber/the whole system (L),V im- mass of fish (kg),is the density of an animal body (by default = 1000 kg/mD^{3})Best wishes,

Sergey

Hi Stefan,

The argument "chamber volume" can be used for both the volume of chamber and the volume of the whole respirometry. Basically, "chamber volume" is the total volume of the respirometry loop.

Thank you for this note, I will clarify this moment in the documentation of the R package.

Yes, it calculates the effective volume as you described in the function calculate.MR. The calculation of absolute metabolic rate is based on the following equation:

*absMO _{2}= *

*Δ[O*(

_{2}]/Δt ×**)**

*V – D × m*where, ** V i**s Volume of a chamber/the whole system (L),

**m**- mass of fish (kg),

*is the density of an animal body (by default = 1000 kg/m*

**D**^{3})

Best wishes,

Sergey