Luminescent DO meters

The Hach HQ10 and HQ20 portable luminescent dissolved oxygen meters are suitable for the measurement of dissolved oxygen (DO) in the field, laboratory or water and wastewater treatment plant process.

The Hach HQ10 and HQ20 portable meters with the LDO probe can be used in any application that traditional polarographic or galvanic DO meters are used, such as aquaculture, environmental monitoring, aeration basins, aerobic and anaerobic digesters and nitrification and de-nitrification tanks, among many others.

The Hach LDO Probe utilises a sensor coated with a luminescent material. Blue light from an LED is transmitted to the sensor surface and excites the luminescent material, which emits red light as it relaxes. The time from when the blue light was sent to when the red light is emitted is measured. The more oxygen that is present the shorter the time it takes for the red light to be emitted. This time is measured and correlated to the oxygen concentration.

Available with 1, 3, 5 and 15 m cable lengths, the LDO probe also includes an integral probe sinking weight and protective shroud for outdoor use. The HQ10 and HQ20 meters meet IP67 waterproof requirements and survive a standard drop-test of 1 m onto concrete.

The easy-to-use meters feature simple one hand operation, intuitive icons and menus and a large, clear backlit LCD. Dissolved oxygen measurements are automatically compensated for barometric pressure via the built-in pressure sensor, as well as automatic temperature and salinity compensation.

Users can data-log up to 500 results either on demand or at user-set timed intervals and durations, with results downloadable to PC or printer through the optional RS232 docking station.

The HQ20 model also features an additional input for either a pH or ORP electrode.