Threshold
Your usage threshold is the amount of energy, in Kwh you will pay the tier 1 rate
for.
Not all gas suppliers offer energy thresholds so it may be necassary to edit this
value if you know you don't have a tiered or staged tariff.
If you pay a single rate for your gas set the threshold to 0 then set the tier 1
rate to zero. Ensure you update your Tier 2 Gas Rate to accurately reflect your
price in pence per unit.
Tier 1 Rate
Your Tier 1 Gas Rate is the top price you pay for each unit, this is normally around
8 pence but varies depending on both your supplier and your tariff.
When not on a tiered gas plan, set this and the threshold to 0 and update your unit
rate in the Tier 2 Rate box.
Tier 2 Rate
The Tier 2 Gas Rate is the lower price you pay for your energy once you have reached
the quarterly threshold set in the threshold box (as a yearly amount).
If you don't have a tiered plan, set threshold and tier 1 rates to 0 then just enter
your price per unit in this box.
Conversion Factor
The conversion factor is a value used to convert meter units into energy (Kwh).
This value will always be visible on your bill.
Calorific Value
The calorific value represents the amount of energy given off when a mass of fuel
if burned.
It can be dependant on several factors including temperature, pressure, the gas
itself and more.
This value can also always be found on your bill.
Volume Correction
Volume Correction or, 'Correction Factor' takes into account changes in the volume
of gas depending on temperature and pressure.