All BroadSensors support RS485 interface and MODBUS protocol and can be directly connected with PLC for use (there is a need to modify the register on PLC according to BroadSensor’s communication definition), it can be directly connected with most of the transmitters or data acquisition instruments with 485 interface. It can also communicate with Kingview software directly. You can refer to BroadSensor’s MODBUS software interface manual for details. For the user’s convenience to be up on BroadSensor, BroadSensor will send the attached demonstration and debugging software of PC with the product, which can read all BroadSensors’ information and print the corresponding data frames for the user engineer’s learning and debugging. The software is the neutral version.

BroadSensor’s COD uses UV LED 254nm optical source coordinating with turbidity compensation optical element to calculate COD content in water by measuring 254nm absorbance. It does not meet China’s environmental standards, but meets Germany’s DIN 38404 national standards. This method has been widely used in Europe and Japan, while in China it has been tried and deployed in small scale.

Because of different measuring principles, the final readings are different. For example, two kinds of equipment respectively use the potassium dichromate method and permanganate method of China’s national standard method to measure the same water sample, the results will have three to five times difference. BroadSensor’s COD calibration method refers to COD equipment of the potassium dichromate method, the consistency and accuracy of BroadSensor’s measuring liquid is the same as the national standard method equipment’s, even better than the national standard method equipment’s on the occasion of zero drift and being less than 30mg/L.

Through site comparison and site calibration, when water composition does not change fiercely, BroadSensor’s COD and the national standard method equipment can reach good consistency and close accuracy.

No reagent of BroadSensor’s COD whose maintenance stage is more than 4 weeks, it is only required to keep the window clean. If it is covered by dirt, please clean the window with diluted hydrochloric acid air-laid paper. As for calibration, it is suggested to use the potassium acid phthalate of national standard to perform calibration for one or two points. The calibration stage is generally once for several months.

Compared with the potassium dichromate method’s calibration steps:

1. Installing the sensor on site, reading the sensor’s reading after the value turns stable, and recording it as X1;

2. Taking the water sample in the sensor’s measuring position, using the potassium dichromate method equipment of national standard to measure it, and recording the reading as Y1;

3. Calculating the user calibration value K=Y1/X1

4. Repeating Step 1 to 3 above within 3 days, calculating the average of K value and writing it into the sensor.

BroadSensor’s COD whose extreme installation depth is 10 meters under water can be installed vertically or horizontally in drop-type. Remembering to fix it in water, keep no barrier around the brush and no foreign substance twining round the brush. It is suggested to select BroadSensor’s COD protection cover to avoid foreign substance’s twining round the brush and resulting in motor invalidation. The motor fault led by foreign substance’s twining will not be covered by the 12-month warranty.