Description
Overview
GAOTek Anemometer with D298 Velocity Probe (Directional Probe) has a multifunctional measurement units to measure the air velocity in the range from 0.4 m/s to 45.0 m/s. It is small in size, light in weight and easy to carry. It provides the four digit LCD which display the accurate measurement results. Beyond with complex and advanced technology it is easy to use. It is widely used in data collection for boiler, refrigeration industry, ventilation duct, environment monitor, navigation measurement, weather forecast, collection of the weather datum for outdoor busywork and fire department.
Key Features
- Data Hold feature for storing 24 groups of data.
- Store and recall the readings
- Low-friction ball-bearing design allows free vane movement.
- Direction measurements
- Air velocity measurements
- Beaufort scale measurements
- Wave height measurements
- Air temperature measurements
- Auto power off function
- Use USB data output and RS232C data output to connect with PC.
Technical Specifications
Air Velocity | |
m/s (meters per sec) | Range: 0.4 m/s ~ 45.0 m/s |
Resolution: 0.1 m/s | |
Accuracy : ±(2 % + 0.1 m/s) | |
Km/h ( kilometers per hour) | Range: 1.4 km/hr. ~ 162.0 km/hr. |
Resolution: 0.1 km/hr | |
Accuracy: ±(2 % + 0.1 km/hr) | |
Ft/min(feet per minute) | Range : 80 ft/min ~ 8860 ft/min |
Resolution: 0.1 ft/min | |
Accuracy: ±(2 % + 1 ft /min) | |
Knots (nautical MPH) | Range : 0.8 knots ~ 88.0 knots |
Resolution: 0.1 knots | |
Accuracy: ± (2% + 0.1 knots) | |
Air Flow | |
CMM (Cubic meters/min) | Range :0 ~ 9999 m3/min |
Resolution: 0.001 to 1 | |
Accuracy: ± (2% + 1 ftm3/min) | |
CFM (Cubic ft/min) | Range : 0 ~ 9999 ftm3 / min |
Resolution: 0.001 to 1 | |
Accuracy: ± (2% + 1 ft3/min) | |
Beaufort Scale | Range : 0 ~ 12 (measured the force) |
Resolution: 0.1 | |
Accuracy: +0.5 | |
Direction | Range :0° ~ 360° (degrees) |
Resolution: 22.5° | |
Accuracy: 22.5° | |
Wave Height | Range :0 ~ 14 m |
Resolution: 0.1 | |
Accuracy: ± 0.1 | |
Air Temperature | Range :32 °F ~ 140 °F (0 °C ~ 60 °C) |
Resolution: 0.1 °F (0.1 °C) | |
Accuracy : 0.9 °F (0.5 °C) | |
General Specifications | |
Display | 0.5 in (13 mm) 4-digits LCD |
Measurement | Air Velocity : m/s, km/h, ft/min, knots |
Air Flow: CMM (m3/ min)
CFM (ft3 /min) |
|
Beaufort Scale: Force | |
Wave Height : m | |
Direction : ° from the North Direction | |
Temp : o C and o F | |
Data Storage | 24 groups |
Sampling Rate | Reading per second approx. |
Sensors | Air Velocity/Flow Sensor: 3-cup probe
Direction probe : Low Friction probe Temperature sensor : Precision thermistor |
Automatic Power Off | 0 ~ 9 minutes set by user |
Data Output | RS232 C Serial Interface |
Power Supply | 4 X 1.5 AAA size batteries |
Dimensions
|
Main instrument:
6.1 in x 2.6 in x 1.1 in (156 mm x 67 mm x 28 mm) Velocity Sensor: 2.5 in x 2.5 in x 4.5 in (65 mm x 65 mm x 115 mm) Direction Sensor: 3.3 in x 2.7 in x 4.5 in (86 mm x 69 mm x 115 mm) |
Weight | 9.17 oz. (260 g) including batteries and probe |
Operating Humidity | Max. 80 % RH |
Operating Temperature | 32 oF to 122 oF (0 oC to 50 oC) |
Applications:
- Data collection for boiler
- Refrigeration industry
- Ventilation duct
- Navigation measurement
- Weather forecast
- Collection of weather datum for outdoor busywork and fire department
3-1 Display
3-2 function key
3-3 Unit selection
3-4 back light
3-5 Power button
3-6 Down/Read button
3-7 Up/Save button
3-8 Delete/Menu button
3-9 Max. Value hold
3-10 External power socket
3-11 RS232C socket
3-12 Velocity probe
3-13 Direction probe
3-14 Socket for direction probe
3-15 Socket for velocity probe
3-16 Max. Value indicator
3-17 Parameter indicator
3-18 Temp. Unit
3-19 B. Scale unit
3-20 Area unit
3-21 Speed and Flow unit
3-22 measurement reading
3-23 Browsing indicator
3-24 Number of reading memorized
3-25 Low battery indicator
3-26 Memory indicator
3-27 Direction indicator
OPERATION
If taking velocity measurements then connect the velocity probe to the velocity socket. If you need to take velocity measurements connect the direction probe to the direction socket.
Air Velocity Measurements
- Select velocity function using the FUNCTION button. The LCD will display Speed when the velocity mode is selected.
- Select the desired air velocity units using the UNIT button. The LCD will reflect the current unit selection (ft/min, km/h. m/s and knots).
- Place the velocity probe in the air current.
- Air velocity will be displayed on the upper line of the LCD.
Air Flow Measurements (CMM/CFM)
- Select flow function using the FUNCTION button. The LCD will display “FLOW” when the flow mode is selected.
- Select the desired air flow units using the UNIT button. The LCD will reflect the current unit selection (m3/min, ft3/min).
- Airflow is based on the specific dimensions of the duct being measured. For the meter to correctly measure CMM (Cubic Meter per Minute m3/min) or CFM (Cubic Feet per minute ft3/min). The user must input the area of the duct. Failing to input the correct area dimensions will result in erroneous readings. To input the area dimension.
- Just press and hold the DEL/MENU key long enough until “AREA” showing on the display and release it. It takes about 8 seconds from pressing the DEL/MENU key.
- The previously stored area value will be displayed on the LCD. Please use UP or DOWN key to change the area value to the correct area dimensions. The longer you press the UP or DOWN key the larger will be the increment of the value. To quit press any key except the UP or DOWN key. This procedure can be carried out whenever required or as each time the area of duct is changed.
- Place the velocity probe in the air flow. Wait approximately 2 seconds for a stabilized Air flow reading. The equation below is used to calculate air flow.
- AIR FLOW = (AIR VELOCITY) X (AREA).
Beaufort scale Measurements
- Select Beaufort scale function using the FUNCTION button. The LCD will display “SCALE” when the flow mode is selected.
- Place velocity probe in the air current.
- Beaufort force or scale will be displayed on the LCD.
Wave Height Measurements
- Select wave function using the FUNCTION button. The LCD will display “WAVE” when the wave mode is selected.
- Place velocity probe in the air current with the yellow dot side of the vane facing the air flow.
- Probable wave height in the sea will be displayed in LCD
DIRECTION MEASUREMENTS
- Select direction function using the FUNCTION button. The LCD will display “DIRECTION” when the direction mode is selected.
- Place the direction probe in the air with the mark in line with north direction on the compass fixed on the direction mode.
- The direction will be displayed on the LCD direction.
AIR TEMPERATURE MEASUREMENTS
- Select Temp function using the FUNCTION button. The LCD will display “TEMP” when the temperature mode is selected.
- Select the desired air temp units using the UNIT button. The LCD will reflect the current unit selection (oF or oC)
- Place the sensor in the air current
- Temperature will be displayed on the LCD
DATA HOLD FEATURES
While taking measurements press the “MAX” button to hold the Maximum reading. The “MAX” indicator will appear on the LCD when the display is in maximum data hold mode. Press “HOLD” again to return to normal operation.
STORING AND RECALLING READINGS
- When in “M” state you can save the reading together with measuring conditions to the memory of the meter by pressing the UP/SAVE key. The display shows “M” while the number of memorized readings increases 1.
- No matter in state or “M” state the memorized data can be browsed by pressing the READ Key. The browsing state is marked in “R” on display. When in “R” state all the readings memorized can be recalled by pressing the UP or DOWN key
- To delete the memorized value in memory just enter the browsing state and locate the reading to be deleted by the UP or DOWN key then press “DEL” key and release it. If there is an “Err0” on the display it indicates there is no reading to delete any more.
HOW TO SET THE TIME OF AUTO POWER OFF
The default factory setting for auto power off is 5 minutes. That means the meter will automatically switched off in 5 mins if the meter is idle for more than 5 mins. This setting can be changed from 1 – 9 mins by following the steps
- Just press and hold the DEL/MENU key long enough till “AUTO” showing on the display then release it. It takes about 10 seconds from pressing the key to display “AUTO”.Note: “ArEA” is initially displayed while pressing ignore this and keep holding the key till “AUTO” displays.
- The previously set value will be displayed on the LCD. Please use UP or DOWN key to change the value to desired time. It can be changed from 1 to 9 mins. To disable the function of auto power off set the setting at 0. It means is manual power off.
- To exit the setting, press any key other than UP or DOWN key. This can be done anytime whenever required to auto power off.
BATTERY REPLACEMENT
- When battery voltage less than approximately 5v. It is necessary to replace the batteries.
- Install the batteries 4X1.5v AAA (UM-4) correctly into the case.
- If the instrument is not to be used for any extended period remove batteries.
USEFUL EQUATIONS AND CONVERSIONS
Area equation for rectangular or square ducts
Area= W X H
Area equation for circular ducts
Circular Duct
A=∏R2
(A=3.14 x R x R)
Cubic equation
CFM (ft3/min) = Air Velocity (ft/min) X Area (ft2)
CMM (m3/min) = Air Velocity (m/sec) X Area (m2) X 60
UNITS CONVERSION TABLE
UNITS | m/s | ft/min | Knot | Km/hr | Mph |
1 m/s | 1 | 196.87 | 1.944 | 3.6 | 2.24 |
1ft/min | 0.00508 | 1 | 0.00987 | 0.01829 | 0.01138 |
1 knot | 0.5144 | 101.27 | 1 | 1.8519 | 1.1523 |
1km/hr | 0.2778 | 54.69 | 0.54 | 1 | 0.6222 |
1mph | 0.4464 | 87.89 | .8679 | 1.6071 | 1 |
BEAUFORT SCALE AND PROBABLE WAVE HEIGHT
Beaufort Number | Wind Description | Wind Speed | Wave Height(m) | |||
Wind | Wave | Knots | m/s | Probable | Max | |
0 | Calm | – | <1 | 0-0.2 | – | – |
1 | Light Air | Ripples | 1-3 | 0.3-1.5 | 0.1 | 0.1 |
2 | Light Breeze | Small wavelets | 4-6 | 1.6-3.3 | 0.2 | 0.3 |
3 | Gentle Breeze | Large wavelets | 7-10 | 3.4-5.4 | 0.6 | 1.0 |
4 | Moderate Breeze | Small waves | 11-16 | 5.5-7.9 | 1.0 | 1.5 |
5 | Fresh Breeze | Moderate waves | 17-21 | 8.0-10.7 | 2.0 | 2.5 |
6 | Strong Breeze | Large waves | 22-27 | 10.8-13.8 | 3.0 | 4.0 |
7 | Near Gale | Large waves | 28-33 | 13.9-17.1 | 4.0 | 5.5 |
8 | Gale | Moderately high waves | 34-40 | 17.2-20.7 | 6.0 | 7.5 |
9 | Strong Gale | High waves | 41-47 | 20.8-24.4 | 7.0 | 10 |
10 | Storm | Very high waves | 48-55 | 24.5-28.4 | 9.0 | 12.5 |
11 | Violent Storm | Exceptionally high waves | 56-63 | 28.5-32.6 | 11.5 | 16 |
12 | Hurricane | Exceptionally high waves | 64-71 | 32.7-36.9 | 14.0 | >16 |