User's Guide Heavy Duty Hot Wire CFM Thermo-Anemometer Model 407119A CFM 73.2 F Ft/min HOLD ESC POWER UNIT / ZERO AVERAGE REC.
Warranty EXTECH INSTRUMENTS CORPORATION warrants this instrument to be free of defects in parts and workmanship for three years from date of shipment (a six month limited warranty applies to sensors and cables). If it should become necessary to return the instrument for service during or beyond the warranty period, contact the Customer Service Department at (781) 890-7440 ext. 210 for authorization or visit our website www.extech.com for contact information.
Specifications General Specifications Display Measurement units Dual function 5-digit LCD Air Velocity: m/s, km/h, ft/min, knots, mph; 3 3 Air Flow: CMM (m /min) and CFM (ft /min);Temperature: °C and °F Data hold Freezes displayed reading Sampling rate Display update rate:1 second (approx.
Meter Description 1. Display 2. POWER button 3. HOLD and ESC button 4. REC and ENTER button 5. UNIT, ZERO, and ▲up arrow button 6. Function and ▼down arrow button 7. AVG. START, CLEAR, and ►right arrow button 8. AREA SET button 9. Tilt stand 10. 1 4 Battery compartment / Cover 2 3 5 11. Tripod mount 7 8 12. LCD contrast adjustment pot 13. System reset switch 14. RS-232 Output terminal 15. DC9V power adaptor 6 11 9 15 14 13 12 10 4 Model 407119A Version 4.
Operation Initialization and Zero procedures (please follow these steps before use) TOP VIEW OF METER Important Note: The meter’s probe locking switch must be in the locked position (with the probe inserted) for the meter to turn on and operate correctly. Refer to the accompanying diagram or the diagram at the top of the meter for switch orientation. LOCKED Position For the best accuracy and for proper operation, the following steps must be performed. 1.
Air Velocity Measurements 1. Follow the Initialization and Zeroing procedures above before continuing. 2. Open the antenna to the desired length. 3. Slide the air velocity sensor cover down. 4. Press the POWER button to turn the meter on. 5. Place the sensor in the air current to be measured. Have the air flow meet the sensor head in the direction of the white dot (as shown in diagram). 6. View the air velocity and temperature readings on the LCD Display.
AVERAGE Feature for the Air Flow Mode In the Average mode, up to 20 readings can be stored and averaged. 1. In the Air Flow Mode (discussed earlier), press the FUNCTION button momentarily until the AVG icon and a ‘zero’ appears on the lower LCD display line. 2. Press the AVG START button to record the current reading. A ‘1’ will appear on the lower LCD line indicating that one reading has been stored. 3. Press the AVG START for up to a total of 20 measurements.
Advance Programming Mode From the Air Velocity mode of operation, press and hold the SET button until the meter beeps and a ‘1’ is displayed. The advanced programming mode is now accessed. The Auto Power OFF Enable/Disable and the Temperature Units selections are available in the advanced programming mode. Use the ESC button to exit this mode at any time. Auto Power Enable/Disable The first parameter in the advanced mode is the Auto Power OFF enable/disable.
PC Interface The 407119A is equipped with a 3.5mm jack (side compartment) for connection to a PC for data acquisition purposes. The meter’s data output is a 16 bit data stream. To obtain PC TM interface cabling and Windows data acquisition software, contact Extech Instruments. Instructions for use are provided with the software. The PC interface cable schematic, data stream protocol, and RS-232 communication settings are provided below. PC Interface Cable schematic Meter PC 3.
Battery Replacement When the battery icon appears on the lower left corner of the LCD display, the four (4) ‘AA’ batteries must be replaced. 1. Remove the rear Phillips head screw 2. Slide off the rear battery compartment 3. Replace the batteries 4. Secure the battery compartment Calibration and Repair Services Extech offers repair and calibration services for the products we sell. Extech also provides NIST certification for most products.
Useful Equations and Conversions Area equation for rectangular or square ducts Height (H) Width (W) Area (A) = Width (W) x Height (H) Area equation for circular ducts Area (A) = Radius x r2 = 3.14 and r2 = radius x radius Where Cubic equations CFM (ft3/min) = Air Velocity (ft/min) x Area (ft2) CMM (m3/min) = Air Velocity (m/sec) x Area (m2) x 60 NOTE: Measurements made in inches must be converted to feet or meters before using the above formulae.
