GENEQ > Meteorology > Anemometers
| IceFree3 Anemometer |
Unheated sensors in icing environments can fail or, even worse, give incorrect data. The electrically heated IceFreeII anemometer's simple, robust design provides a proven and reliable solution. Made of cast aluminum with black anodized finish, the anemometer efficiently transfers heat from constant temperature, self-regulating heaters. The signal output is a sine wave varying in amplitude and frequency with wind speed. Patented off-axis correction minimizes errors in measuring up-slope or down-slope winds. The sensor's pinch clamp base mounts easily to a 27mm (1.05") diameter mounting pipe. The IceFreeII's heater is powered by 24V AC or DC, making it compatible with a wide range of remote site equipment. An optional 120/240 VAC to 24 VAC transformer is also available. |
| Specifications | |
| Description | |
| Sensor type | 3 cup heated anemometer |
| Applications | * wind resource assessment * wind turbine control * meteorological studies * ski area maintenance * environmental monitoring |
| Sensor range | maximum rated wind speed is 90 m/s (200 miles per hour) |
| Instrument compatibility | all NRG loggers |
| Output signal | |
| Signal type | variable amplitude sine wave, frequency proportional to wind speed |
| Transfer function | m/s = (Hz x 0.572) + 1.00 [miles per hour = (Hz x 1.28) + 2.24] |
| Sensor to Sensor Variation | 99.7% of sensors fall within 4.3% of stated transfer function (based on over 800 samples) |
| Calibration | available upon request - contact NRG for more information. |
| Output signal range | 0 Hz to 155 Hz |
| Power requirements | |
| Heater supply voltage | * 24 V AC/DC * optional transformer available |
| Heater supply current | * Inrush: 8 A maximum * Steady state: 1 A at 20 °C (68 °F), 4 A under maximum thermal load (head frozen in clear ice then powered on) |
| Response characteristics | |
| Distance constant (63% recovery) | 7.6 m (25 feet) |
| Installation | |
| Mounting | mounts to a 27 mm (1.05 inch) diameter (3/4 inch IPS) pipe with a 5/16 inch nut and bolt; cabling exits into mounting pipe |
| Tools required | 13 mm (0.5 inch) nut driver |
| Environmental | |
| Operating temperature range | -40 °C to 60 °C (-40 °F to 140 °F) |
| Operating humidity range | 0 to 100% RH |
| Physical | |
| Connections | Signal Cable * clear: signal * black: ground * shield drain Heater Cable * black / white: heater power (AC/DC) |
| Cable length | * Signal & Power cables: 2.8 m (9.2
feet) * extension kits available |
| Weight | 1.45 kg (3.2 pounds) |
| Dimensions | * overall assembly height : 224 mm (8.82
inches) * body diameter: 70 mm (2.75 inches) * swept diameter of rotor: 127 mm (5 inches) |
| Materials | |
| Cups | precision balanced aluminum with black anodized finish and heat-resistant black paint |
| Body | cast aluminum with black anodized finish and heat-resistant black paint |
| Shaft | centerless ground, stainless steel |
| Bearing | stainless steel ball bearings with application specific lubrication |
| Magnet | 4 pole ceramic |
| Coil | single coil, shielded for ESD protection |
| Cable | * Signal: 2 conductor 20 AWG, chrome PVC
jacket with overall foil shield and drain * Heater: 2 conductor 20 AWG, Teflon jacket with braid shield and drain |
| Enclosure | * sealed to IP55 * heater is epoxy encapsulated to IP65 |
| Heater | fully encapsulated, self-regulating |
| Base | cast aluminum with black anodized finish and heat-resistant black paint |