• Ascension is designed with a filter-first design. All fluid transport and measurement systems (fluidics, flow meter, pump) are located downstream of the filters to reduce the need for disinfectants or bleach onboard.

• Standard 47mm diameter disc filters of various materials (MCE, stainless steel, fiberglass, nylon, etc.) are compatible. We recommend using filters between 10µm and 1000µm pore size depending on the calibration range of your flow meter.
• *Note: If your samples will be analyzed in our Microplastics Laboratory, contact us for filter requirements.

• Ascension can be deployed down to 400 meters depth in environments between 0°C and 40°C.

• In late 2022, we standardized around the new pinch valve design in favour of higher-pressure pumping and eliminating instrument-induced contamination which only allows one 47mm filter housing to be loaded per channel. Reach out to our support team to discuss whether your specific filter type could be accommodated in a stacked configuration.

• Follow the Pre-Deployment checklist, including charging the battery, preparing and purging filters, inspecting the instrument and tether, and initializing your deployment using the Ascension Desktop app. Checklists and detailed setup instructions can be found above.

• Ascension should be rinsed, flushed, and drained after every deployment to remove contaminants and prevent buildup. Use the built-in automated Flush Routine with fresh water and empty filter housings to clean the internal fluidic system.

• The filter vacuum test is performed out in the field immediately before priming to verify proper seal integrity of filter housings and prevent sample contamination or measurement errors.

• Inspect the filter housing for leaks. Ensure the filter housing is screwed together fully but not overtightened. Check to ensure the white valve tubing is intact (no cuts or holes). Refer to the troubleshooting guide in the Instrument Manual (page 93).

Purging the instrument and filter housings ensures that there is no air in the system before deployment. This is important for several reasons:

• Air bubbles can accumulate on the surface of some filters, reducing their effective surface area and filtration efficiency.
• Some fine mesh filters, such as Mixed Cellulose Ester (MCE), are susceptible to rapid changes in humidity. When these filters are exposed to air bubbles after suspension in water, the porous structure can deform or even close, resulting in blocked filter pores. To avoid this, filters should be purged fully inside the filter housing by following the purging procedure in the instrument manual.
• Air bubbles compress and expand as the instrument moves through the water column, which can apply pressure to the fluidic system inside the instrument.
• Air bubbles can impact the accuracy of the flow meter readings.

• Filters saturate when the pores clog from the accumulation of suspended material. This process happens gradually as water is pumped across the filter. When a filter becomes saturated, the flow rate will taper off to zero and the volume over time plot in the Manual Deployment windows will show a flat line.
• Ascension can detect filter saturation on its own during an automated deployment. If a filter saturation condition is reached before the target volume/time is achieved, the instrument will automatically stop the pump and move on to the next sample action as programmed.

• In Manual Mode, data is recorded on the connected PC. In Automated Mode, data is stored onboard the instrument and can be offloaded post-deployment. Ascension automatically records a copy of the Manual Deployment data onboard the instrument that can be retrieved post-deployment should your PC shutdown or lose connection during deployment.

• Ascension is designed in a way so that only one valve may be opened at a time to ensure accurate flow rate and volume measurements are recorded for each filter.

• Failure to install the vent port plug before submerging the instrument will cause permanent, catastrophic damage to the instrument core and internal electronics. Any damage caused by failure to install the vent port plug is not covered by the instrument warranty.

• The valve actuator must be “homed” after the instrument is turned on to calibrate the valve mechanism. The action of homing the valve actuator ensures all valves are closed and ready to be opened when instructed. To home the valve actuator, open the Real Time Controller within the Ascension Desktop app, and select the Home Position in the drop-down menu inside the Sample Channel Selector Then click Open Valve button.

• This is normal valve actuator behaviour. The valve actuator will open and close each valve between the previously opened valve and the home position as it moves to calibrate itself.

• Ascension toggles valves open and closed during operation. If a valve isn’t closed before powering off the instrument, it will be left open even after the instrument is switched off. It is recommended to home the valve mechanism before powering off the instrument to ensure that all valves are closed during transportation and storage.

• In late 2022, we standardized around the new pinch valve design in favour of higher-pressure pumping and eliminating instrument-induced contamination which only allows one 47mm filter housing to be loaded per channel. Reach out to our support team to discuss whether your specific filter type could be accommodated in a stacked configuration.

• After uploading, click the retrieve mission script button to read the active mission from the instrument. When loaded in, you can review the mission script to ensure it matches what you intended.

• After uploading a new automated mission script, a pop-up window will appear asking whether you’d like to set the instrument into Automated Mode immediately.
• If you do not set the instrument into Automated Mode immediately after uploading an automated mission script, you can switch Ascension into Automated Mode through the Realtime Controller (Control -> Realtime Controller) by clicking the dropdown menu and selecting Auto.

• Ascension will end a sample early if the flow rate drops below the flow meter’s minimum detection threshold or if the battery is depleted.

• Store Ascension in a dry environment with the vent plug removed. Discharge the battery in both the instrument and tether spool to ~30 – 50% and follow the winterization steps in the checklists/instrument manual.

• Follow the Ascension Shipping Instructions above. They will run you through everything from discharging the battery to meet IATA requirements to labelling your case with the required dangerous goods labels.

• Consistent rapid blinking indicates Lockdown Mode, typically due to low battery. Charging is required before resuming operation.

• Confirm the tether spool is powered on and the status LED is blinking green.
• Confirm the instrument is powered on and the status LED is flashing blue.
• Ensure Bluetooth is enabled on your computer and the ODI Tether is paired in your Bluetooth settings.
• Try restarting Ascension Desktop and reconnecting via File -> Connect Profiler (Bluetooth).

• The pinch valves can become sticky when left unused in a dry environment for a long time. Exercising the sliding mechanism while submerged in water helps to relubricate the underwater bearings. Move the valve back and forth with your fingers repeatedly once it is submerged to get things moving freely again. We do not recommend applying any lubricants other than water to the valve mechanism.

• Verify that the pump throttle is set appropriately (60 - 100% for impeller style pump).
• Ensure the instrument and filters were properly purged of air.
• Inspect for leaks in the fluidic pathway or improperly seated filter housings/fluidic connection points.
• Check to confirm the fluidic system fitting is plugged into the bottom of the flow meter.
• Verify the pump is spinning.
• If the volume plot appears sporadic, it’s likely that air bubbles are passing through the fluidic system. Confirm that both the instrument and filter housings were purged before deployment.
• Check the flow meter calibration coefficients within the settings window in Ascension Desktop to ensure they match the coefficients printed on the back of your flow meter.

• If no commands are received for 20 minutes (default), Ascension enters a tri-tone alarm mode to alert the user that it has been left powered on.
• This time duration can be changed in the instrument settings via Ascension Desktop.

• Environmental factors such as ocean currents, wind, and vessel movement can influence the angle and trajectory of the tether through the water column. If Ascension does not reach the desired depth within reasonable deployment conditions, try adding weight to the instrument to reduce drift.

• You can add a maximum of 5kg (10lbs) of additional weight to Ascension. Ensure the dry weight of Ascension plus any auxiliary components/weight does not exceed 14kg (30lbs). Surpassing this limit may damage the tether and risk failure.