The 5-day Biochemical Oxygen Demand (BOD5) test requires that samples be incubated for a period of 5 days between the initial reading of dissolved oxygen, and the final reading. The environment the samples are incubated in must be strictly controlled at 20°C for the entirety of the 5 days, and the best option for establishing this environment is an incubator. There are a wide variety of incubators available in the market with different dimensions and volumes, accommodating more or less samples depending on a laboratory’s requirements.
MANTECH’s BOD Pro analyzer automates the preparation and analysis of sets of samples for this BOD5 test using a multi-position autosampler along with pumps and other components. MANTECH’s AM400 autosamplers all accommodate 12- position or 18-position racks which the operator places the sample bottles into, then starts the run. After the analysis is complete, the operator applies stoppers and overcaps to the bottles according to the Standard Methods, and the sample bottles are placed in the incubator. For the BOD Pro systems, it is greatly beneficial to keep the bottles in position on the racks and place the full racks in the incubator, to save time and effort for the operators.
The dimensions of an 18-position BOD rack with bottles, stoppers and overcaps applied are provided below:
L – 19in/49cm
W – 9in/23cm
H – 7.5in/19cm
The dimensions of a 12-position BOD rack with bottles, stoppers and overcaps applied are provided below:
L – 19in/49cm
W – 6in/15cm
H – 7.5in/19cm
When sourcing an incubator for your lab’s BOD analysis, you will want to consider the total number of bottles expected to be analyzed every week, as well as the number of racks those bottles will occupy. For example, if your lab analyzes 200 BOD bottles every week, this would correspond to 12 18-position racks, with the last rack only being partially filled but still taking up the space of a full rack in the incubator.
Some examples of recommended incubator models and their bottle capacities both including racks, and not including racks, are provided below:
| Brand | Model # | Description | Capacity with 18-position Racks | Capacity with 12-position Racks | Capacity w/o Racks | Link |
| Fisher Scientific | S50441A | Economy Standard Incubator, 19.8 L, Aluminum | x | x | 12 | https://www.fishersci.ca/ |
| Fisherbrand | 15-015-2633 | Microbiological Incubator, 60 L, Stainless Steel | x | x | 75 | https://www.fishersci.ca/ |
| Fisherbrand | 15-015-2634 | Microbiological Incubator, 117 L, Stainless Steel | x | x | 108 | https://www.fishersci.ca/ |
| Fisherbrand | 15-015-2645 | Microbiological Incubator, 180 L, Stainless Steel | 108 | 108 | 144 | https://www.fishersci.ca/ |
| Fisherbrand | 15-103-1569 | Isotemp™ 400 Refrigerated Incubator, 381 L, Stainless Steel | 252 | 252 | 343 | https://www.fishersci.ca/ |
| Fisherbrand | 3720A | Isotemp™ BOD Refrigerated Incubator, 566 L, Porcelain Steel | 288 | 384 | 441 | https://www.fishersci.ca/ |
| Thermo Scientific | 13-262-340 | Forma™ Environmental Chamber Model 3920, 821.2 L, Stainless Steel | 432 | 576 | 792 | https://www.fishersci.ca/ |
