When should I use an optical DO sensor (RBRcoda³ T.ODO) rather than a galvanic DO sensor (OxyGuard)?
Normally for short duration deployments (days to weeks) we recommend the OxyGuard sensor, but for deeper and longer deployments, we recommend the RBRcoda3 T.ODO.
The RBRcoda3 T.ODO | fast is recommended for all profiling applications because the time constant (1s) is will provide better performance when profiling through oxygen gradients.
Both the galvanic cell sensor and the optode sensor are accurate instruments. The optode is more expensive than the galvanic cell sensor, but is more stable for long-term moored measurements, and does not require periodic refurbishment and recalibration. The Oxyguard has a lower initial cost, but does require periodic refurbishment and recalibration by the end user to maintain its accuracy.
| RBRcoda3 T.ODO | RBRcoda3 DO (OxyGuard) |
|---|---|
| More expensive | Less expensive (low initial cost) |
| More stable long-term | Less stable |
| Does not require periodic refurbishment and recalibration by the end user | Requires periodic refurbishment and recalibration by the end user (extra expense) |
| | fast option for profiling | Not for profiling |
| Shallow and deep deployments | Shallow deployments |