| Model | PHB-3 Tester | 5021 Conductivity Tester |
| Range | 0 ̴ 14 .OpH | 0 ̴ 10.00 mS/cm Auto. Ranging |
| Resolution | 0.1 pH | 0.1/1 μs: 0.01 mS |
| Accuracy | 0.1 ± pH ±1 dight | ±2% FS |
| ATC | No | Yes |
| Calilbration Solution | Yes | Yes |
| Power | AAA betteries x2, 1.5Vx2 | |
| Dimension and weigh | 39 x 25 x 176 mm | |
| Model | 5031 TDS Tester | 5041 ORP Tester | 5051 Salinty Tester |
| Range | 0 ̴ 5.00 ppt Auto. Ranging | ±1000 mV | 0 ̴ 14 .OpH |
| Resolution | 0.1/1 ppm: 0.01 ppt | 1 mV | 0.01 ppt |
| Accuracy | ±2% FS | ±0.5% | ±2% FS |
| ATC | Yes | No | Yes |
| Calilbration Solution | Yes | No | Yes |
| Power | AAA betteries x2, 1.5Vx2 | ||
| Dimension and weigh | 39 x 25 x 176 mm | ||
