Operation guide for dissolved oxygen analyzer

The dissolved oxygen analyzer can be used for both laboratory analysis and on-site analysis. All connections between the analyzer and electrodes are safe and waterproof.

The dissolved oxygen analyzer can be used for both laboratory analysis and on-site analysis. All connections between the analyzer and electrodes are safe and waterproof. When the light is dim, the instrument screen can emit background light and enlarge the font displayed on the screen. In addition, a sturdy and durable on-site toolbox is optional. This makes on-site measurement extremely convenient.

1、 Preparation before using dissolved oxygen analyzer:

1. Preliminary probe inspection

① Remove the red and black plastic covers, as they are designed for shipping purposes and can be discarded.

② Soak the bottom 2.5cm of the probe in electrolyte to wet the sensor.

③ Gently shake the electrolyte to rinse the film, and then fill it with clean electrolyte; Lightly tap the edge of the film with your fingertips to ensure there are no bubbles and to separate from the water.

④ To avoid damaging the film, do not directly tap the bottom of the film.

⑤ Ensure that the rubber O-ring is accurately located inside the membrane cover.

⑥ Turn the sensor face down and twist the film cover clockwise, some electrolyte will overflow.

2. Calibration of dissolved oxygen analyzer

To achieve high accuracy, it is recommended to calibrate the instrument regularly. The calibration procedure for instrument standards usually consists of two values: 0.0% (zero point) and 100% (slope). Instrument calibration is simple. Before calibration, ensure that the probe is installed correctly and in a measurable state. Preliminary preparation: Pour a small amount of HI7040 zero oxygen solution into a beaker, and if possible, use a plastic beaker to reduce EMC interference. Ensure that the electricity is measurable. Press the ON/OFF button to turn on the instrument. For calibration, it is recommended to wait for 15 minutes and adjust the power. Set the appropriate height coefficient and set the salinity coefficient to zero.

⑴ Zero point calibration

① Insert the electricity into HI7040 zero oxygen solution and gently stir for 2-3 minutes

② Press the CAL key, the "~" symbol and the word "NOT READY" will flash until the reading stabilizes

③ Once the reading is stable and the deviation is within the range u, start flashing "CFM" and press the CFM key to confirm the "0.0%" reading

④ Press the CAL key, the instrument will return to measurement mode and record zero calibration data.

⑵ Slope calibration is recommended to be performed in air. Clean the electricity with plenty of clean water to remove any residual zero oxygen solution.

① Dry the battery and wait for a few minutes for the reading to stabilize. The "~" symbol and "NOT READY" will flash until the reading stabilizes.

② Once the reading stabilizes, the "CFM" starts flashing. Press the "CFM" key to confirm the "100.0%" D.O. value.

③ Once the reading is stable and within the deviation range. The instrument will save the data (while adjusting the slope point), record the zero calibration data, and return to measurement mode.

④ If the reading is not close to the selected value, the word "WRONG" will flash. If the reading exceeds the range, the word "WRONG" will flash simultaneously.

2、 Operation of dissolved oxygen analyzer

1. DO measurement ensures that the instrument has been calibrated, the protective cover is removed, and then the probe is immersed in the sample solution being measured. At the same time, ensure that the temperature sensor is also immersed in the sample and wait for the reading to stabilize (about 1 minute). The dissolved oxygen value is displayed on the main screen, and the temperature is shown on the lower screen. Press the RANGE key to convert the value between ppm and saturation percentage.

2. The temperature measuring instrument has a built-in temperature probe, and before measurement, the probe should be brought to thermal equilibrium with the outside world, which may take a few minutes. The larger the temperature difference, the longer the required time.

① If there is a "---" and the words "NO Probe" flashing on the screen, it indicates that the dissolved oxygen probe is connected incorrectly or the measured temperature exceeds the range, and it is also possible that the probe is damaged.

② If the measured temperature exceeds the range, the word "℃" will flash.

③ If the reading exceeds the range, all range values or flashing will occur

④ Ensure that the instrument has been calibrated before measuring the sample

⑤ To successfully measure multiple samples and obtain readings, thoroughly clean the probe with deionized water before immersing it in the sample.