MMP8 can also output ppm, the average mass concentration of water in oil. Vaisala has this conversion readily available for specific oils, including mineral transformer oil. This allows continuous measurement of ppm concentration in power transformer condition monitoring.
The table below lists the oil solubility coefficients of the oil types that can be used for the MMP8 probe.
| Oil type | Oil 0 (A) | Oil 1 (B) |
|---|---|---|
| Mineral oils (for example, Shell Diala, Nynas Nytro) | -1662.70 | 7.3694 |
| Midel 7131 | -687.54 | 5.6236 |
| FR3 | -684 | 5.3318 |
| Dow Corning 561 | -1248.64 | 6.5427 |
After installing the MMP8 probe, configure the coefficients using the Insight PC software or the Indigo80 handheld indicator.
For determining the coefficients using your own apparatus, see Determining Oil-specific Coefficients for Moisture in Oil Probes Technical Note (M212935EN).