| Model | ZD-20A | ZD-50A | ZD-200A | ZD-200AS | ZD -400A | ||
| Measurement principle | 90˚ Scattered light | ||||||
| Measuring range (NTU) | 0~20 | 0~50 | 0~200 | 0~200 | 0~200,200~400 | ||
| Indication accuracy | 0.01 | 0.01 | 0.01 | 0.1 | 0.01 | ||
| Indication stability | ±1.5%(F.S 30min) | ||||||
| Zero drift | ±1.5%(F.S 30min) | ||||||
| Repeatability (linearity error) | ≤2% | ||||||
| Indication error (basic error) | ±8% | ±6% | |||||
