1. Introduktion
The BTMETER BT-881W is a versatile digital instrument designed for measuring environmental conditions. It functions as both a heat stress meter and an anemometer, providing accurate readings for Wet Bulb Globe Temperature (WBGT), wind speed, ambient temperature, and relative humidity. This device is suitable for a wide range of applications, including HVAC maintenance, drone operation, dust collection systems, and monitoring heat stress in various indoor and outdoor environments such as boiler rooms, mining areas, military training, and outdoor sports activities.
Nøglefunktioner omfatter:
- Multifunctional measurement of wind speed, wind temperature, relative humidity, and WBGT.
- High accuracy for all measurements.
- WBGT alarm function with adjustable thresholds.
- Indoor/Outdoor WBGT measurement modes for precise heat stress index.
- Support for 5 air velocity units (m/s, Ft/min, Knots, Km/h, Mph) and 2 temperature units (Celsius/Fahrenheit).
- Data hold function and backlit LCD display.
- Automatisk slukfunktion.
2. Produktet er slutview og komponenter
The BT-881W meter is designed for handheld use and features a clear LCD display. It includes a black ball sensor for WBGT measurement and a wind speed sensor (impeller).

Figure 1: BTMETER BT-881W Heat Stress Meter Anemometer with indicators for WBGT Temp, Wind Speed, Wind Temp, Humidity, WBGT Alarm, and 5 Wind Speed Units.

Figur 2: Detaljeret view of the BT-881W, showing the ABS Black Ball WBGT sensor, Wind Speed Sensor, and Backlit On/Off feature. Dimensions are approximately 208.3mm (height), 52mm (width), and 40mm (depth).
Pakken indeholder:
- 1 x BTMETER BT-881W Heat Stress Meter
- 1 x brugermanual
- 1 x bæretaske
3. Opsætning
3.1 Batteriinstallation
The BT-881W requires one 9V battery (not included). To install the battery:
- Find batteridækslet på bagsiden af enheden.
- Åbn låget.
- Insert a 9V battery, ensuring correct polarity.
- Luk batterirummets dæksel forsvarligt.
3.2 Tænd/sluk
Press the power button (usually marked with a power symbol) to turn the device on or off. The device features an auto power-off function to conserve battery life.
3.3 Montering af stativ
The device includes a 1/4" screw hole at the bottom for mounting on a tripod, allowing for stable and hands-free measurements.

Figure 3: The BT-881W can be mounted on a tripod using the 1/4" screw hole for stable measurements.
4. Betjeningsvejledning
4.1 Switching Measurement Modes (MODE Button)
Tryk på MODE button to switch between the main display for wind speed measurement and WBGT measurement. This allows you to focus on the specific environmental parameter you need to monitor.
4.2 Selecting Indoor/Outdoor WBGT Mode (OUT/IN Button)
In WBGT display mode, press the UDE I button to switch between indoor and outdoor WBGT measurement modes. This adjustment helps in obtaining more accurate heat stress index readings by accounting for differences in temperature, humidity, and direct or radiant sunlight.
4.3 Changing Wind Speed Units (WIND Button)
Tryk på VIND button to cycle through the available wind speed units: meters per second (m/s), feet per minute (Ft/min), knots (Knots), kilometers per hour (Km/h), and miles per hour (Mph).

Figure 4: The BT-881W supports 5 wind speed units for diverse measurement needs.
4.4 Switching Temperature Units (℃/℉ Button)
Tryk på ℃ / ℉ knappen for at skifte mellem temperaturenheder Celsius og Fahrenheit.
4.5 Data Hold Function (MAX/MIN Button)
De MAX/MIN button can be used to hold the current measurement data on the display, allowing for easy recording or observation.
4.6 Setting WBGT Alarm (SET Button)
The device can alert you with WBGT alarms when the black globe temperature (TG) level reaches a set threshold (20~50℃). To set the alarm temperature:
- Enter WBGT mode using the MODE knap.
- Tryk på SÆT knappen for at gå ind i alarmindstillingstilstand.
- Use the up/down arrow buttons to adjust the alarm temperature value.
- When the WBGT alarm is triggered, the backlight color changes to red, indicating a potential heat stress hazard.

Figure 5: The BT-881W provides visual indications for different WBGT hazard levels: Caution (26.7-29.4°C), Extreme Caution (29.4-31°C), Danger (31-32.2°C), and Extreme Danger (>32.2°C).
4.7 Baggrundsbelyst display
The LCD display features a backlight for improved visibility in low-light conditions. This feature is automatically activated or can be controlled as per the device's design.
5. Produktdemonstration
Video 1: A comprehensive demonstration of the BTMETER BT-881W Heat Stress Meter Anemometer, including unboxing, battery installation, wind tunnel testing for accuracy, tripod mounting, and detailed explanations of button functions such as MODE, OUT/IN, WIND, SET, and ℃/℉. The video also illustrates the WBGT alarm feature and its visual indicators.
6. Vedligeholdelse
- Rensning: Brug en blød, tør klud til at rengøre enheden. Brug ikke slibende rengøringsmidler eller opløsningsmidler.
- Opbevaring: When not in use for extended periods, remove the battery and store the device in a cool, dry place, preferably in its carrying pouch.
- Sensorpleje: Keep the wind speed sensor (impeller) and the black ball sensor free from dust and debris to ensure accurate readings. Avoid physical impact to the sensors.
7. Fejlfinding
- Enheden tændes ikke: Kontroller, om 9V-batteriet er installeret korrekt og har tilstrækkelig opladning. Udskift batteriet om nødvendigt.
- Unøjagtige aflæsninger: Ensure sensors are clean and unobstructed. Verify that the correct measurement mode (Indoor/Outdoor WBGT) and units are selected. Allow the device sufficient time to stabilize in the measurement environment.
- Problemer med skærm: If the display is dim or flickering, the battery may be low. Replace the battery.
8. Specifikationer
| Feature | Detalje |
|---|---|
| Mærke | BTMETER |
| Modelnummer | BT-881W |
| Produktdimensioner | 2.05 x 1.57 x 8.19 tommer |
| Varens vægt | 5 ounces (0.31 pund) |
| Strømkilde | Battery Powered (1 x 9V battery required, not included) |
| Materiale | Plast |
| Display Type | LCD |
| Måleområde for vindhastighed | 0~30 m/s |
| Wind Temperature Measurement Range | 0~50 ℃ |
| Relative Humidity Measurement Range | 0.1%~99.9% RH |
| WBGT Temperature Measurement Range | 32~122 °F (0~50 °C) |
| Temperatur nøjagtighed | ±0.6 ℃ (±2 ℃ overall) |
| Fugtighedsopløsning | 0.1% RF |
| Vindhastighedsnøjagtighed | ±5 % |
| Speciel funktion | Portable, WBGT Alarm, Backlit LCD |
9. Garanti og support
The BTMETER BT-881W comes with a 365-day quality warranty and lifetime technical support. For any inquiries or assistance, please contact BTMETER customer service.