Extech MO290 Pinless Moisture Psychrometer
The Extech MO290 Pinless Moisture Psychrometer gives building inspectors and restoration teams a practical way to measure moisture and climate conditions with one handheld instrument. It combines pin and pinless moisture testing with psychrometric calculations and infrared temperature measurement. As a result, users can check materials quickly and reduce the need to carry several meters.
This versatile meter helps identify damp areas before damage becomes visible. The pinless sensor scans up to 19 mm below the surface without marking finished materials, while the included pin probe allows direct contact readings when needed. In addition, the clear LCD screen shows readings at a glance and uses an icon bar to indicate moisture levels.
Built for Site Surveys
During inspections, the Extech MO290 Pinless Moisture Psychrometer measures relative humidity, air temperature, dew point, vapour pressure and grains per pound values. The built-in infrared thermometer covers surface temperatures from -20 to 200 °C and uses an 8:1 distance to spot ratio. Therefore, users can compare surface and ambient conditions in a single pass.
Audible alarms increase in speed as moisture levels rise, helping users react quickly to changing conditions. The instrument also performs an internal self-test during start-up and checks battery status automatically. Consequently, you can begin work with confidence and spend less time on setup.
Designed for Reliable Results
The Extech MO290 Pinless Moisture Psychrometer features a durable ABS housing with a protective rubber boot for daily field use. Its dual display presents important information clearly and the threaded pins can be replaced to extend service life. Furthermore, the meter stores data logically so trends can be reviewed with ease.
Two different set types are available to suit different applications. One version is supplied with the MO290-P pin moisture probe for contact measurements, while the standard configuration focuses on the integrated measurement functions. Both options provide a convenient all-in-one solution for moisture investigation and building diagnostics.
Key Features
- Combines pin and pinless moisture measurement methods
- Measures relative humidity and air temperature
- Calculates dew point and condensation point values
- Displays grains per pound and vapour pressure readings
- Includes a built-in infrared thermometer
- Uses an 8:1 distance to spot ratio for surface checks
- Provides a variable rate audible moisture alarm
- Shows low medium and high moisture conditions with an icon bar
- Performs an automatic internal verification routine at start-up
- Checks battery condition automatically
- Features replaceable threaded moisture pins
- Stores readings for easier trend comparison
- Designed for wood and other building materials
- Supplied with a protective soft carry pouch
- Available in two different set configurations
Technical Specifications
| Manufacturer | Extech |
| Manufacturer part code | MO290 |
| Moisture measurement modes | Pin WME 0 to 99.9% and pinless relative 6 to 99.9% |
| Pinless measurement depth | Up to 19 mm or 0.75 in |
| Relative humidity range | 0 to 100% RH with ±3% basic accuracy |
| Air temperature range | -29 to 77 °C (-20 to 170 °F) |
| Infrared temperature range | -20 to 200 °C (-4 to 392 °F) |
| Dew point range | -30 to 100 °C (-22 to 199 °F) |
| Vapour pressure range | 0 to 20.0 kPa |
| Water vapour content | 0 to 999 gpp and 0 to 160 g kg⁻¹ |
| Optical ratio | 8:1 distance to spot |
| Emissivity | Fixed at 0.95 |
| Sensor type | Non-penetrating electromagnetic pad and replaceable threaded pins |
| Display | Back-lit dual LCD with icon bar |
| Alarm | Variable rate audible beeper linked to moisture level |
| Power supply | One 9 V alkaline battery included |
| Housing | Impact resistant ABS with protective rubber boot |
| Dimensions | 235 x 63 x 38 mm |
| Weight | 265 g including battery |
| Operating conditions | 0 to 50 °C below 80% RH non-condensing |
| Storage conditions | -20 to 60 °C below 75% RH |
| Warranty | One year manufacturer’s warranty |
Comparison Table
| Feature | Standard MO290 | MO290 Set with MO290-P Probe |
|---|---|---|
| Pinless moisture measurement | ✓ | ✓ |
| Infrared thermometer | ✓ | ✓ |
| Psychrometric measurements | ✓ | ✓ |
| Pin moisture readings | — | ✓ |
| Remote pin moisture probe included | — | ✓ |
| Measures wood moisture by pin method | — | ✓ |
Document Downloads
What’s Included
- Extech MO290 Pinless Moisture Psychrometer
- 9 V alkaline battery
- Protective soft carry pouch
- Protective rubber boot
- MO290-P pin moisture probe where supplied as part of the set version