USER GUIDE Large Vane CFM/CMM Anemometer / Psychrometer Model AN310
Introduction Congratulations on your purchase of the Extech AN310 Vane Airflow Anemometer Psychrometer. This instrument measures Air Velocity, Air Flow (volume), Air Temperature, Relative Humidity, Wet Bulb Temperature, and Dew Point Temperature. The large, easy‐to‐read backlit LCD includes primary and secondary displays plus numerous status indicators. The optional round and square airflow cone allows for quick volume measurements.
Meter Description Meter Description (front) 1. Top line LCD display reading 2. Bottom line LCD display reading 3. U/mode AVG and up arrow button 4. L/mode and down arrow button 5. ON‐OFF (Power) and SET button 6. HOLD, MAX‐MIN, and left arrow (Enter) button 7. Unit of measure symbol for lower display row 8. Unit of measure symbol for upper display row 9. Air Velocity Vane Meter Description (rear) 10. Air temperature and humidity sensors 11. Battery compartment 3 AN310-EU-EN V1.
Brief Keypad Description Press momentarily to switch the meter ON or OFF. Press and hold this button for 2 seconds to enter or exit the Setup mode (refer to Setup mode section for details).
Display Layout 1. Lower Display digits (air volume, temperature, timer, or menu parameter displays) 2. Upper Display digits (air velocity, humidity, or menu display parameters) 3. Optional Cone attachment icon 4. Units of measure for duct area programming 5. Vane indicator (flashes very briefly on power up) 6. Display HOLD icon 7. MAX mode icon 8. MIN mode icon 9. Recording icon 10. Elapsed Timer icon 11. AVG mode icon 12. Battery status icon 13. Unit of measure icons* *Full list shown.
Operation Air Velocity and Air Volume Measurements 1. Switch the meter ON by pressing the POWER button again to switch the meter OFF. button momentarily. Press the POWER 2. Note that the meter will automatically enter the sleep mode after 20 minutes of inactivity. To disable this feature: with the meter OFF, press and hold the POWER and the U/mode buttons for 2 seconds. The LCD will display 'n' as it switches ON.
Relative Humidity, Wet Bulb, and Dew Point Measurements The relative humidity sensor is built in to the center of the vane (rear of meter) and can be used to measure relative humidity, dew point and wet bulb temperatures. 1. Press U/mode to switch to the %RH display if necessary. The measured humidity readings will be displayed on the upper LCD digits. 2. Use the L/mode button to scroll through air temperature, dew point temperature, wet bulb temperature, and air volume readings. 3.
Timed Average Mode 1. From the normal operating mode, press and hold the U/mode button for 2 seconds to enter the Multi‐Point Average mode first and then press U/mode one more time momentarily to enter the Timed Average Mode (the AVG and the elapsed timer icons will switch ON). 2. Press HOLD to begin recording. The elapsed timer starts (as shown on the upper display digits) and the clock icon flashes on and off. 3. Press U/mode to stop the clock and to calculate the timed average.
Battery Replacement When appears on the LCD, the AAA batteries must be replaced. The battery cover is located on the back of the meter. 1. Open the rear battery compartment by carefully pulling down on the compartment’s latch. 2. The battery compartment cover should be completely removed before proceeding. 3. Replace the four (4) 1.5V ‘AAA’ batteries ensuring proper polarity. 4. Close the battery compartment before attempting to use the meter.
Specifications Air Velocity Ranges Resolution Accuracy m/s (meters per sec) 0.2 – 30 m/s 0.01 m/s ± (1.5%rdg + 0.3 m/s) fpm (feet per minute) 40 – 5900 fpm 1 fpm ± (1.5% rdg + 59 fpm) Range Resolution Accuracy 0.1%‐99.9%RH 0.1 RH ±3%RH (10‐90%RH) Ranges Resolution Relative Humidity RH ±5%RH (<10% or >90%) Air Flow CMM (cubic meters/min) 0‐99999 m3/min CFM (cubic ft/min) 0‐99999 ft3/min Temperature Ranges 0.1 up to 9999.9 then 1.0 0.1 up to 9999.9 then 1.
Error Messages Error codes and solutions Air Temperature E02: Temperature reading is lower than the low range limit. Place the meter in room temperature for 30 minutes. If E02 continues, send the unit to Extech for repair. E03: Temperature exceeds the high range limit. Place the meter in room temperature for 30 minutes. If E03 continues to appear, send the unit to Extech for repair. E31: The A‐to‐D converter requires replacing. Send the meter to Extech Instruments for repair.
Appendix: Useful Equations and Conversions Area equation for rectangular or square ducts Height (H) Area (A) = Width (W) x Height (H) Width (W) Area equation for circular ducts 2 Area (A) = pi x r 2 Where pi = 3.14 and r = radius x radius Radius Cubic equations 3 2 CFM (ft /min) = Air Velocity (ft/min) x Area (ft ) 3 2 CMM (m /min) = Air Velocity (m/sec) x Area (m ) x 60 NOTE: Measurements made in inches or centimeters must be converted to feet or meters before using these formulae.
