Not only are fish, corals and invertebrates utilizing oxygen in your tank, nitrifying bacteria in your biological filter are using it too. Milwaukee's Dissolved Oxygen meter delivers a precise and accurate electronic measurement of the oxygen content currently in your tank. Reads from 0-19.9 ppm. Accurate to + 1.5%.
Specifications Aquarium Type FRESH AND SALT WATER
Instructions Probe preparation: Slide off the battery compartment cover on the back of the meter. Install the battery (included) while paying attention to its polarity.
NOTE: The D.O. probes are shipped dry. To hydrate the probe and prepare it for use, connect it to the meter and proceed as follows: Remove the red and black plastic cap. This cap is used for shipping purposes only and can be thrown away. Wet the sensor by soaking the bottom 1 in. of the probe in electrolyte for 5 minutes. Rinse the membrane (supplied with the meter) with electrolyte while shaking it gently. Refill with clean electrolyte. Gently tap the sides of the membrane with your finger tip to ensure that no air bubbles remain trapped. To avoid damaging the membrane, do not tap the membrane directly on the bottom. Place rubber O-ring properly inside the membrane cap. With the sensor facing down, screw the cap clockwise. Some electrolyte will overflow. When not in use and during polarization, replace the protective cap supplied with the meter.
Probe polarization: The probe is under polarization with a fixed voltage of approximately 800 mV. Probe polarization is essential for stable measurements with the same recurring degree of accuracy. With the probe properly polarized, oxygen is continually consumed by passing through the sensitive diaphragm and dissolving in the electrolyte solution contained in the probe. If this operation is interrupted, the electrolyte solution continues to be enriched with oxygen until it reaches an equilibrium with the surrounding solution. Whenever measurements are taken with a non-polarized probe, the oxygen level revealed is both that of the tested solution as well as that present in the electrolyte solution. This reading is incorrect.
Calibration procedure: Calibration is simple and fast. Make sure the probe is ready for measurements, i.e. the membrane is filled with electrolyte and the probe is connected to the meter. Switch the meter on by pressing the on/off key. For an accurate calibration, it is recommended to wait at least 15 minutes to ensure conditioning of the probe. Remove the protective cap from the D.O. probe.
Zero calibration: Dip the probe into Zero Oxygen Solution and stir gently for 2-3 minutes. Allow the LCD readout to stabilize. Adjust the zero D.O. calibration trimmer (located on the back of the meter) until the display reads 0.0.
Slope calibration: It is suggested to perform the slope calibration in saturated air. Rinse the probe with a large amount of clean water to remove any residual zero oxygen solution. Dry the probe tip and allow a few minutes for the LCD readout to stabilize. Press and hold the CAL key. Adjust the slope trimmer on the front panel of the meter to read 100% on the LCD (while still holding the CAL button). Release the CAL key and the LCD will display the value in ppm of oxygen. The zero calibration is very stable, therefore this procedure needs only to be performed whenever the probe is replaced. However, because the slope calibration is more critical, it is recommended to perform this procedure every week.
Taking measurements: Make sure the meter has been calibrated and the protective cap has been removed. Immerse the tip of the probe in the sample to be tested. For accurate measurements a water movement of 0.3m/second is required at minimum. This is to ensure that the oxygen-depleted membrane surface is constantly replenished. A moving stream will provide adequate circulation. To quickly check if the water speed is sufficient, wait for the reading to stabilize and then move the probe. If the