- Out-of-Stock
MMP8 catalogue
Smart Moisture in Oil Probe MMP8
745.43KB
Vaisala MMP8 Moisture in Oil and Temperature Probe
The Vaisala MMP8 provides continuous online measurement of dissolved moisture and temperature in transformer oil, lubrication oil, hydraulic fluid and other liquid hydrocarbons.
- Measures water activity from 0 to 1 aw, relative saturation, temperature and ppmw
- Dry-end accuracy up to ±0.01 aw or ±1%RS
- Temperature measurement from −40 to +180 °C
- Available in standard 262 mm and long 448 mm probe versions
- Adjustable insertion depth with ISO 1/2 or NPT 1/2 process fittings
- Standalone Modbus RTU or connection to Vaisala Indigo transmitters
Continuous Moisture Measurement Directly in Oil
The Vaisala MMP8 measures dissolved moisture directly in a flowing or static oil system. It is designed for transformer oil, lubrication systems, hydraulic fluids, oil purification equipment and other applications where early detection of water ingress helps protect the oil, machinery and process.
The probe reports water activity, relative saturation and temperature. It can also calculate water concentration in ppmw when suitable oil-solubility coefficients are available. Because the measurement intelligence is built into the probe, MMP8 can communicate directly with a control system or connect to a Vaisala Indigo transmitter or Indigo80 handheld indicator.
Choosing the system: Use MMP8 alone where the control system accepts Modbus RTU. Add an Indigo transmitter when the installation requires a local display, analogue outputs, relays, Ethernet, Modbus TCP or additional wiring and power-supply options.
Standard or Long MMP8?
| Selection point | Standard MMP8 | Long MMP8 |
|---|---|---|
| Overall probe length | 262 mm | 448 mm |
| Adjustable insertion depth | 35 to 193 mm | 35 to 379 mm |
| Typical use | Standard pipelines, transformer valves and compact oil-system installations | Large pipes, tanks or installations requiring a deeper measurement point |
| Weight with 2 m cable | Approximately 510 g | Approximately 610 g |
| Marine type approval | DNV GL certificate applies | DNV GL certificate does not apply to the 448 mm version |
| Selection check | Confirm the required insertion depth and external service clearance | Confirm that the additional probe length can be safely inserted and removed |
Measurement Performance
| Specification | MMP8 performance |
|---|---|
| Water-activity range | 0 to 1 aw |
| Specified water-activity accuracy | ±0.01 aw, equivalent to ±1%RS, from 0 to 0.5 aw under specified conditions |
| Response time | 10 minutes, T90, at +20 °C in still oil |
| Moisture sensor | Vaisala HUMICAP® 180L2 |
| Temperature range | −40 to +180 °C |
| Temperature accuracy at +20 °C | ±0.2 °C |
| Water concentration | Typical ppmw accuracy of 10% of the reading when suitable oil coefficients are used |
| Output parameters | Water activity, relative saturation, temperature and water concentration in oil |
| Calibration certificate | Traceable calibration at five moisture points and one temperature point |
Operating and Mechanical Specifications
| Specification | MMP8 provision |
|---|---|
| Probe-head temperature | −40 to +180 °C |
| Probe-body temperature | −40 to +80 °C |
| Operating pressure | 0 to 40 bar absolute |
| Pressure during insertion | Up to 10 bar absolute |
| Ball-valve operating limit | Up to +100 °C and 40 bar absolute |
| Process fittings | ISO 1/2 or NPT 1/2 |
| Probe-body protection | IP66 |
| Probe material | AISI 316L stainless steel |
| Standard probe cable | 2 m FEP-jacketed cable |
| Electrical connector | M12 5-pin A-coded male |
| Filter options | Standard stainless-steel grid or grid for oil-flow rates above 1 m/s |
Standalone Output and Indigo Connectivity
| Connection method | What it provides | Suitable when |
|---|---|---|
| MMP8 standalone | 15 to 30 VDC supply and non-isolated RS-485 with Modbus RTU | The PLC, data logger or control system can communicate directly with the probe |
| Indigo200 | Compact display with model-dependent analogue outputs, relays or Modbus RTU | A practical single-probe local transmitter is required |
| Indigo300 | Industrial metal enclosure, local display and up to three configurable analogue outputs | A rugged single-probe transmitter is preferred |
| Indigo510 | One-probe flagship transmitter with two isolated analogue outputs and Ethernet connectivity | A robust single-probe plant installation is required |
| Indigo520 | Two probe connections, four isolated analogue outputs, two relays and Ethernet connectivity | Two measurements or expanded automation integration are required |
| Indigo80 | Portable display, data logging, diagnostics and probe configuration | Spot checks, field diagnostics or portable moisture-in-oil measurement are needed |
| Vaisala Insight | Probe configuration, diagnostics, data viewing and field calibration | A service computer is available at the measurement location |
MMP8, MMT310 or MMT330?
| Instrument | Main strength | When to consider it |
|---|---|---|
| MMP8 | Interchangeable smart probe with standalone Modbus RTU and full Indigo compatibility | New modular installations, portable work with Indigo80, or migration from legacy MMT330 systems |
| MMT310 Series | Compact fixed transmitter with two analogue outputs and RS-232C | Established installations requiring a compact permanently connected transmitter |
| MMT330 Series | Legacy full-size transmitter platform | Existing-unit identification and migration planning only; use MMP8 with Indigo for new projects |
| MMP8 with Indigo transmitter | Separates the calibrated probe from the display and system-interface hardware | Applications requiring maintainability, selectable outputs and future probe interchangeability |
Typical Moisture-in-Oil Applications
| Application | Measurement objective | Important consideration |
|---|---|---|
| Power transformers | Monitor dissolved moisture and the risk of free-water formation | Choose a representative oil-circulation point and confirm the required ppm coefficients |
| Lubrication systems | Detect water ingress before it affects the oil or rotating equipment | Trend moisture together with temperature and operating condition |
| Hydraulic systems | Track moisture that can shorten fluid and component life | Review pressure, temperature, flow and fitting compatibility |
| Oil dryers and purifiers | Measure drying performance and control treatment cycles | Compare inlet and outlet readings under stable process conditions |
| Marine machinery | Monitor moisture in lubricating and hydraulic oils | Use the standard 262 mm version where DNV GL type approval is required |
| Paper and process industries | Detect ingress and support preventive maintenance | Select an accessible measurement point with continuous oil exchange |
Water Activity, Relative Saturation and ppm
Water activity, aw, indicates how close the oil is to moisture saturation at its present temperature. Relative saturation expresses the same relationship from 0 to 100%RS. A rising value shows that the oil is moving closer to the condition where free water can form, even when the absolute amount of water has not changed.
Water concentration in ppmw estimates the mass of water in the oil. The calculation depends on the water-solubility characteristics of the specific oil. Vaisala provides coefficients for several transformer oils, while other oils may require verified oil-specific coefficients. These can be configured using Vaisala Insight or Indigo80.
Vaisala MMP8 Supplier and Technical Support in Malaysia
Seacom Process Instruments supplies and supports the Vaisala MMP8 Moisture in Oil Probe in Malaysia for transformer oil, lubrication systems, hydraulic fluids, oil dryers, marine machinery and other demanding industrial applications.
Our team can assist with standard or long probe selection, process fittings, ball-valve installation, Indigo transmitter selection, Modbus integration, oil-specific ppm coefficients, commissioning and calibration planning. We can also review replacement arrangements for existing MMT330 and MM70 systems.
Need help selecting the right configuration? Send Seacom the oil type, temperature, pressure, pipe size, process connection, insertion depth, required outputs and whether the measurement will be fixed or portable. We will help check the suitable MMP8 and Indigo arrangement.
You might also like
The Vaisala Indigo200 Series is the standard transmitter platform for one interchangeable Indigo-compatible smart probe, providing local display and practical automation-system connectivity.
- Indigo201 with three analog outputs and two relays
- Indigo202 with Modbus RTU and two relays
- Colour display with numerical and graphical views
- IP65 enclosure for industrial measurement applications
The Vaisala Indigo300 is a rugged industrial transmitter for one Vaisala Indigo-compatible smart probe, providing local measurement display and up to three configurable analog outputs.
Its corrosion-resistant IP66 metal enclosure, flexible probe mounting and interchangeable probe design make Indigo300 suitable for humidity, temperature, dew point, CO2, moisture in oil and other demanding industrial measurements.
The Vaisala Indigo500 Series provides flagship industrial measurement integration: choose Indigo510 for a simplified single-probe system or Indigo520 for full dual-probe capability.
- Indigo510: one probe and two isolated analog outputs
- Indigo520: two probes, four isolated outputs and two relays
- Ethernet web interface and Modbus TCP communication
- Rugged IP66 and NEMA 4 metal enclosure
Vaisala HUMICAP® MMT310 Series provides continuous online measurement of moisture and temperature in transformer, lubrication and hydraulic oils.
The compact transmitter measures water activity (aw) or relative saturation (%RS), showing how close the oil is to forming free water. Optional ppm calculation is available for mineral transformer oil and configured oil types.
- Models MMT317 and MMT318
- Water activity range: 0 to 1 aw
- Temperature range: -40 to +180°C
- Two configurable analogue outputs and RS-232C
- Up to 40 bar with MMT318 and ball-valve installation
- IP66 compact transmitter enclosure
- Traceable calibration certificates included
The Vaisala MMT330 Series provided continuous measurement of moisture and temperature in transformer oil, lubrication oil, hydraulic fluid and other liquid hydrocarbons.
- Discontinued series; not recommended for new installations
- Legacy MMT332, MMT337 and MMT338 probe configurations
- Measures water activity, relative saturation, temperature and calculated ppm
- Graphical display, data logging and versatile analogue or digital outputs
- Used for oil-condition monitoring, dryer control and free-water risk detection
- Use Vaisala MMP8 with an Indigo transmitter for new installations
6 other products in the same category:
The Vaisala MM70 was a portable meter for spot-checking water activity and temperature in transformer, lubrication and hydraulic oils.
- Discontinued product; not recommended for new purchases
- Legacy MI70 handheld indicator with MMP78 moisture-in-oil probe
- Water-activity measurement from 0 to 1 aw
- Temperature measurement from −40 to +100 °C
- Direct insertion through a ball valve without draining the process
- Numerical display, trend graph and portable data logging
The Vaisala MMT330 Series provided continuous measurement of moisture and temperature in transformer oil, lubrication oil, hydraulic fluid and other liquid hydrocarbons.
- Discontinued series; not recommended for new installations
- Legacy MMT332, MMT337 and MMT338 probe configurations
- Measures water activity, relative saturation, temperature and calculated ppm
- Graphical display, data logging and versatile analogue or digital outputs
- Used for oil-condition monitoring, dryer control and free-water risk detection
- Use Vaisala MMP8 with an Indigo transmitter for new installations
The Vaisala Indigo300 is a rugged industrial transmitter for one Vaisala Indigo-compatible smart probe, providing local measurement display and up to three configurable analog outputs.
Its corrosion-resistant IP66 metal enclosure, flexible probe mounting and interchangeable probe design make Indigo300 suitable for humidity, temperature, dew point, CO2, moisture in oil and other demanding industrial measurements.
The Vaisala Indigo200 Series is the standard transmitter platform for one interchangeable Indigo-compatible smart probe, providing local display and practical automation-system connectivity.
- Indigo201 with three analog outputs and two relays
- Indigo202 with Modbus RTU and two relays
- Colour display with numerical and graphical views
- IP65 enclosure for industrial measurement applications
Vaisala HUMICAP® MMT310 Series provides continuous online measurement of moisture and temperature in transformer, lubrication and hydraulic oils.
The compact transmitter measures water activity (aw) or relative saturation (%RS), showing how close the oil is to forming free water. Optional ppm calculation is available for mineral transformer oil and configured oil types.
- Models MMT317 and MMT318
- Water activity range: 0 to 1 aw
- Temperature range: -40 to +180°C
- Two configurable analogue outputs and RS-232C
- Up to 40 bar with MMT318 and ball-valve installation
- IP66 compact transmitter enclosure
- Traceable calibration certificates included
The Vaisala Indigo500 Series provides flagship industrial measurement integration: choose Indigo510 for a simplified single-probe system or Indigo520 for full dual-probe capability.
- Indigo510: one probe and two isolated analog outputs
- Indigo520: two probes, four isolated outputs and two relays
- Ethernet web interface and Modbus TCP communication
- Rugged IP66 and NEMA 4 metal enclosure