BTMETER BT-846A Pro CFM Anemometer Wind Gauge — Black, Detachable Extendable Vane, 600-Set Data Logging

BTMETER's BT-846A Pro CFM anemometer is a handheld wind-speed and airflow meter that records up to 600 measurement groups and exports data to a PC for HVAC balancing and troubleshooting.

This compact, professional-grade wind gauge combines a detachable extendable vane sensor with a large backlit LCD and wide measurement ranges for velocity, temperature and volumetric flow. It supports five wind speed units and displays CFM/CMM air volume after you enter the duct or register cross-sectional area. The unit stores readings locally for later export, making it useful for systematic airflow diagnosis, documentation and quality-control tasks.

How accurate and wide-ranging are the wind and temperature measurements?

The BT-846A measures wind speed from very low air movement to strong flows, with fine resolution and stated accuracy suitable for HVAC and ventilation checks. Air temperature is tracked alongside velocity so you can account for thermal effects when calculating volumetric flow.

• Wind speed range: 0.001 to 100 mph with 0.001 resolution and ~3% accuracy plus 0.2 reading.
• Speed units available: m/s, km/h, ft/min, knots, mph.
• Temperature range: 32–113°F (0–45°C) with 0.1° resolution.

What airflow and volume calculations can it perform for ducts and registers?

The meter converts measured velocity into volumetric flow when you enter the area of the duct or register, displaying results in CFM or CMM. This saves time on manual math and helps standardize airflow checks across multiple vents or systems.

• Airflow range: 0–999,900 ft³/min (CFM) with adaptive resolution from 0.001 to 100.
• Accepts area inputs from 0.001 to 9,999 ft² for on-the-fly CFM/CMM calculation.
• Provides live Current, Max, Min, 2/3 Max and Average flow values for comparative diagnostics.

How does the detachable extendable sensor help during HVAC balancing?

The separate extendable vane allows you to position the sensor in registers or tight spaces while keeping the main instrument visible. Because the sensor can be replaced independently, maintenance is simpler and the tool has longer service life on the job.

• Extendable sensor lets you read the display while probing deep vents or balancing registers.
• Detachable design enables quick replacement if the vane is damaged.
• Large 1.69 x 2.36 inch backlit LCD makes measurements easy to read in dim mechanical rooms.

Can I store and analyze measurements later?

Yes — the BT-846A stores up to 600 groups of readings and can export the dataset to a PC for documentation or deeper analysis. This feature helps when producing reports, comparing before-and-after balancing results, or keeping records for compliance.

• Onboard memory holds 600 measurement groups for batch review.
• Export capability to PC for spreadsheet or reporting workflows.
• Manual or automatic power-off conserves battery during intermittent use.

Who is this for: The BTMETER BT-846A is built for HVAC technicians, building engineers, facility maintenance teams and ventilation contractors who need reliable, portable airflow and wind-speed measurement with data-logging. It also fits use by home performance specialists, environmental testers and anyone who requires repeatable CFM/CMM readings and exportable records for inspections or quality control.

Included features:

• 5 wind speed units and temperature in °C/°F.
• CFM/CMM volumetric calculations after area input.
• 600-set memory and PC export for record keeping.
• Detachable extendable vane sensor, backlit LCD, carrying case and replaceable sensor design.