Hach Ultra ORBISPHERE 510, Operator'S Manual

Page: 137 / 144

Orbisphere 510/511/512 Analyzers - Glossary 131 of 138
Operator Manual
ORBISPHERE
Appendix A: Glossary
A.1 Gas Units
Table A-1: Gas Units
Unit Meaning
% air
percentage, by weight. A concentration of 100% air corresponds to liquid
saturated with air at current pressure and temperature. The equivalent
concentration of O
2
is approximately 20% O
2
in normal conditions.
% O
2
percentage, by weight. A concentration of 100% O
2
corresponds to liquid
saturated with pure O
2
at current pressure and temperature.
%Vbar
ratio in percent between the partial pressure of gas measured and the
atmospheric pressure
%Vext
ratio in percent between the partial pressure of gas measured and the
external pressure. Available when an external pressure sensor is present.
µg/L micrograms per liter
atm atmosphere
bar, mbar bar, millibar
cc/kg
volume of gas per kg of liquid. The volume of gas is calculated considering
normal conditions (T = 0°C, p = 1atm)
g/kg grams per kilogram
g/m
3
grams per cubic meter
mg/L milligrams per liter
ml/L milliliters per liter
Pa, hPa, kPa Pascal, hecto Pascal, kilo Pascal
ppb parts per billion, by weight
ppm parts per million, by weight (same as mg/kg)
ppm Vb
parts per million, per volume, barometric pressure referenced.
= %Vbar / 10,000
ppm Ve
parts per million, per volume, external pressure referenced.
= %Vext / 10,000
psia pound per square inch, absolute
V / V volume per volume (ratio)