Quick Guide for using a 1-CUBE
GMA Dissolved CO
2
Carbonation Analyser
for Beer and Cider
Also read the User’s Guide
To start measuring the dissolved CO
2
in a sample,
first take a sample from a tank
as follows:
It will help if you watch this YouTube video:
https://www.youtube.com/watch?v=z_M7LpkEv1Q
1) Direct the outlet hose to a suitable drain or waste beer collection container
2)
To clean any debris
from inside the tank outlet valve,
open the tank sampling valve
. Allow
beer to flow out to waste for a short time.
Close the tank sampling valve
.
3)
Connect the inlet hose
to the tank sampling valve. If necessary, secure with a clip or cable tie to
achieve a gas tight seal. Remember to allow for the pressure in the tank, it will be applied to the
hose.
4)
Fully Open the tank sampling valve
and
Fully Open
the
GMA inlet valve
5)
Gently Open
the
GMA outlet valve
until beer starts to flow.
Adjust the outlet valve
until a slow
and steady flow is achieved to flush through and fill the chamber with new beer. Normally allow
the beer to flow for at least 30 seconds, and until the beer flows clear in the chamber.
6) Fully
Close the GMA outlet valve
. Then
Fully close the inlet valve.
You now have your sample for analysis with the instrument, but the beer in the chamber is under
pressure, notice the gauge. This excess pressure must be released, otherwise our equilibrium pressure
reading will be wrong
.
7)
Open the outlet valve for a short time
(about 1 sec.)
Close the valve
. Excess gas will have
released. The pressure should now be about zero or just above.
8)
Rotate and unlock the black plunger
on top of the GMA, so that the plunger can move up &
down. Notice the position of the white dot and the locked position.
9)
Fully lift the plunger and push down hard, repeat for THREE full strokes
in quick
succession. (Only three times. No more and no less!). NOTE: On each stroke you will see gas
being released from solution inside the chamber.
10) After the third down stroke rotate and
lock the plunger
11) In theory partial pressure equilibrium has been reached. Notice how the pressure in the chamber
has increased. This is because dissolved gas has come out of solution.
12) Switch on the digital thermometer and
read the temperature
.
13)
Read the pressure in kPa
14) To calculate the dissolve CO
2
content,
line up the pressure and temperature
on the rotary
nomogram on the base of the instrument.
Read off the CO
2
content in g/l
NOTE: 1 g/l = 0.506 %vol. 1%vol = 1.976 g/l.
To measure another tank, re-connect the GMA and repeat the steps above. The new beer sample
will push out the previous beer.
Continued…please read on, cleaning is important!
INLET
OUTLET
CO
2
release PLUNGER
Digital Thermometer
Pressure Gauge
Note the inlet tube
GMA
by 1-CUBE
