In terms of measurement performance, these instruments typically have a wide measurement range. For example, the 9187sc has a measurement range of 0.010 - 2 ppm (mg/L), while some portable instruments can reach a range of 0.05–20.00 mg/L. Instruments using selective membrane sensors have strong anti-interference capabilities, are unaffected by chlorine, bromine, hydrogen peroxide, and ozone, and have high measurement accuracy. Some online instruments (such as the 9187sc) have sensors with built-in temperature probes that can automatically compensate for water temperature fluctuations of 0-45℃, reducing measurement errors. Regarding use and maintenance, online instruments require minimal maintenance, generally requiring calibration every two months and replacement of the electrolyte and membrane every six months.
Portable instruments emphasize ease of operation. For example, they are based on Android smart systems with built-in process prompts, making operation intuitive; data can be uploaded to a cloud platform via WiFi and Bluetooth for easy management; they have excellent waterproof performance; they are lightweight (some weigh only 230 grams), support AC/DC power supply and built-in batteries, making them suitable for field testing. In addition, the instruments are highly automated, capable of automatically diagnosing faults, calibrating automatically, and storing data automatically (some can store more than 80,000 records). Some models have a built-in mini thermal printer that can print reports in real time.
