Introduction - General HWA4214SD User Manual

INTRODUCTION

Thank you for purchasing General Tools & Instruments' HWA4214SD Hot Wire Anemometer-
Thermometer with Datalogging SD Card. Please read this user's manual carefully and
thoroughly before using the instrument.
The HWA4214SD is a general-purpose handheld instrument that can make two kinds of
measurements:
• Air (wind) speed and temperature (simultaneously)
• Surface temperature, as measured by an optional Type K or Type J thermocouple
All hot wire anemometers, including the HWA4214SD, have at their heart a very thin metal
wire that the instrument electrically heats up above ambient temperature. Air flowing past
the wire cools it. The speed of the air flow can be calculated from the relationship between
the metal's electrical resistance and temperature. In the HWA4214SD, the hot wire is
located at the end of a telescoping probe, where it is paired with a tiny glass bead
thermistor that measures air temperature.
Compared to other types of anemometers, hot wire anemometers have superior
performance. For this reason, they are commonly used for precise measurement of
low-speed air flows, turbulent flows, or of any flow in which rapid velocity fluctuations
are of interest. Applications include:
• Environmental testing
• Maintenance and repair of air conveyors and flow hoods in clean rooms
• Measurement of air velocity produced by fans and blowers
• Balancing velocity profiles in furnaces and refrigerated cases
• Operating paint spray booths
The HWA4214SD comes with a telescoping air speed-temperature probe. Air speeds can
be displayed in m/s (meters/second), fpm (feet per minute), km/h (kilometers/hr), knots
(nautical miles per hour), or mph (miles per hour). Temperatures can be displayed in oF
(Fahrenheit) or oC (Celsius) units.
Several features and capabilities enhance the instrument's versatility. Among them are
automatic temperature compensation for measurements made by the telescoping probe
or by Type K or J thermocouples, the ability to hold readings and display maximum and
minimum readings, and an automatic power off function that extends battery life.
Because it is microprocessor-based, the HWA4214SD can make full use of the portability,
reliability and large storage capacities that SD memory cards offer. Measurements can be
made automatically at any sampling rate between one second and one hour. After storing
and time-stamping the measurements on an SD card plugged into the instrument (a
process called datalogging), the user can remove the card and plug it into to a laptop or
desktop computer either directly or via a USB card reader. The data logs are stored on the
card as files with the .xls extension, which can be opened by Microsoft's Excel application.
The HWA4214SD has a backlit 2.5 in. diagonal display and is powered by six "AA" Alkaline
batteries or an optional 9-VDC AC adapter.
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