In most natural waters N2 and O2 are the dominant dissolved gases. If oxygen is measured independently, pN2 can be determined from gas tension. The two gases together can be used to make substantially improved estimates of net biological production.
Total dissolved gas measurements have also been used to study air-sea gas exchange and other upper ocean physical, chemical and biological processes.
Also available is the HGTD-Pro™ hurricane model which is a smaller, lighter sensor that equilibrates faster that the GTD-Pro™.
How stable is the GTD-Pro™? One GTD-Pro™ was repeatedly deployed over a period of 6 years at depths up to 120 meters, first in the Labrador Sea, then in the Equatorial Pacific and North Pacific. Over that 6 year period, the GTD-Pro™ drifted from calibration by less than 0.001% per year. Not every GTD-Pro™ will be this stable, but all are guaranteed to drift no more than 0.02% per year.
|Length:||35 cm||22.9 cm|
|Diameter:||10 cm||8.3 cm|
|Weight:||3 kg in air, 0 kg in water||1.6 kg in air, 0.6 kg in water|
|Housing:||Delrin® (300 m depth)||Delrin® (300 m depth)|
All of our instruments are covered by a ONE-YEAR LIMITED WARRANTY
Accuracy: < 0.02 mbar / yr drift
Resolution: 0.002 mbar
Equilibration time (t63): 3 min (GTD-Pro)
1 min (HGTD-Pro)
Sample rate: 1 second (user selectable with datalogger / controller)