How to Change the Membrane and Electrolyte Solution in the Q46 and Q46 Series:

Step 1: Remove the Sensor from the Flow Cell

The Q46 and Q45 sensors are typically installed in a constant-head flow cell, ensuring stable readings. Start by:

1. Unplugging the Electrical Connector: Located at the back of the sensor.
2. Removing the Sensor: Pull it out gently, and the O-ring seal will release it smoothly.

With the sensor in hand, let’s move on.

Step 2: Replace the Membrane

To access the membrane and solution:

1. Unscrew the Ring and Remove the Membrane: Take off the ring, discard the old membrane, and empty any remaining electrolyte.
2. Prepare the New Membrane: Retrieve a new membrane from its container, removing the yellow protective paper.
3. Insert the New Membrane: Place the clear membrane inside the ring and secure it by threading the ring and cap back together until fingertight.

Step 3: Add Electrolyte Solution

With the new membrane in place:

1. Fill the Cap with Electrolyte Solution: Fill to the bottom of the threads.
2. Prepare the Sensor for Reassembly: Remove the small side screw for easier reattachment.

Step 4: Reassemble the Sensor and Cap

To ensure the sensor functions correctly:

1. Attach the Cap at a 45° Angle: Thread the sensor and cap together, allowing some electrolyte to spill out—this is normal.
2. Tighten Until Sensor Contacts the Membrane: Tighten until the sensor tip just touches the membrane.
3. Replace the Small Plastic Screw: Reinsert and gently tighten the screw.

Step 5: Reinstall the Sensor

Once assembled:

1. Reconnect to the Flow Cell: Press the sensor back into the O-ring seal.
2. Plug in the Electrical Connector: Reattach the connector.

Warm-Up and Calibration Tips

After changing the electrolyte solution, allow the sensor a few hours to warm up before calibration. Trying to calibrate during warm-up may result in shifting readings. In some setups, replacing the electrolyte solution and membrane alone restores calibration without adjustments.

Watch our video tutorial for a full demonstration!