The HI 9146 is state-of-the-art, heavy-duty DO meter, designed to provide laboratory results and accuracy under harsh industrial conditions. This instrument is provided with a series of new diagnostic features and messages on the LCD which add an entirely new dimension to the measurement of DO, by allowing the user to dramatically improve the reliability of the measurement.

The Auto Endpoint feature automatically freezes the display when a stable reading is reached.

Dissolved Oxygen is indicated in ppm (parts per million) or in %. All measurements are automatically compensated for temperature. Salinity compensation in water allows direct determination of Dissolved Oxygen in saline waters and altitude compensation readjusts for the altitude variance. The Dissolved Oxygen probe has a membrane covering the polarographic sensors and a built-in thermistor for temperature measurements and compensation. This permeable PTFE membrane isolates the sensor elements from the testing solution, but allows Oxygen to pass through. When a voltage is applied across the sensor, oxygen that has passed through the membrane reacts causing a current flow, and hence determining a reading.

The Battery Error Preventing System (BEPS) detects when the batteries become too weak to ensure reliable measurements. The backlight feature is automatically disabled when batteries are getting low and a clear indication is displayed to warn the user of this condition. However, the meter continues to measure correctly even when the low battery indication is displayed. The meter automatically switches itself off when the batteries are too weak to support proper function. In addition, the meter allow the user to enter an ID code to uniquely identify the instrument.hout prior notice