| Model | SI-136 Portable Model |
| Display | LCD Display |
| Range pH | 0 to 14.00 |
| Resolution pH | ±0.01 mV |
| Accuracy pH | ±0.01 mV |
| Compensation Manual | 0 to 100º C |
| Power | 1 × 9 V Battery |
| Dimensions | 165 × 85 × 28 mm |
| Location | Worldwide |
| Brand Name | Spectronics India |
| Model | SI-139 |
| Display | 3 1/2 Digit LED |
| Range (pH) | pH 0 to 14.00 mV 0 to + 1999 |
| Resolution (pH) | 0.01 mV 1 |
| Accuracy (pH) | pH ±0.01 mV ±1 |
| Temperature Compensation | Manual 0 to 100o |
| Slope Correction | 80 to 120% |
| Power | 230V ±10% |
| Dimensions | 275 x 175 X 76 |
| Location | Worldwide |
| Brand Name | Spectronics India |
| Model | SI-143 Auto Temp. |
| Display | 3 1/2 digit LED |
| Range (pH) | 0 to 14.00 mV 0 to ±1999 |
| Resolution (pH) | 0.01 mV 1 |
| Accuracy (PH) | ±0.01 mV ±1 |
| Temperature | Manual and Automatic (ATC) |
| Compensation | 0 to 100 |
| Slope Correction | 80 to 120% |
| Power | 230v ± 10% ac, 50 Hz |
| Dimension | 275 x 175 X 76 |
| Location | Worldwide |
| Weight | 100-200gm, 200-300gm, 300-400gm, 400-500g |
| Feature | Accuracy, Light Weight, Lorawan Compatible, Low Power Comsumption, Multi Jet |
| Voltage | 3-6VDC, 6-9VDC, 9-12VDC |
| Display Type | Digital |
| Frequency | 50Hz-65Hz |
| Automatic Grade | Automatic |
| Power Source | Electric |
| Warranty | 2Years |
| Location | Worldwide |