Omega WMS-16 manual Introduction, Sensors

INTRODUCTION

Congratulations on your purchase of a WMS-16 Weather Station, and welcome to the world of modular, user friendly weather data collection. The WMS-16 has been carefully designed with the user in mind, and we are confident that it will provide you with convenient and accurate weather data for years to come.

The WMS-16 is a state-of-the-art, microprocessor-based weather station that provides capabilities unequaled in similarly priced instruments. In its standard configuration, measurements for wind speed, direction, temperature, humidity, and precipitation are collected and processed by the control module.

Any, or all, of these weather parameters can be included by simply adding the appropriate sensors. The exact configuration is determined by the user based on demands of the intended application.

Data Output, Display, and Logging

Real-time weather data is output by the WMS-16 over its RS- 232 interface, and this data can be readily viewed by either using a PC based communications program or with the optional software for the WMS-16. In addition to current weather information, the WMS-16’s data logging capability allows up to 45 days of data taken at 15 minute intervals to be stored in memory for later retrieval.

Special consideration has been given in the design of the WMS-16’s display of current weather data to ensure ease of understanding by the first-time or casual user.

Current Observations

This display is a one-page report of current weather conditions, with each parameter clearly labeled and readily located on the screen.

In addition to the measured parameters, the

WMS-16 also calculates values for wind chill and dew point based on the combination of weather factors that govern those characteristics. The WMS-16 also reports specific aspects of the measured parameters, including peak wind speed, wind direction variation, hourly temperature change, maximum and minimum daily temperature, barometric pressure changes, maximum and minimum daily pressure, relative humidity change and daily and monthly precipitation accumulation.

Data Logging

The time interval between recordings is user determined for periods ranging from one minute to sixty minutes. This logged data can be retrieved for display or copied to a floppy or hard

WMS-16 Weather Station Operator’s Manual 1

disk for permanent storage using the options available on the main menu.

When retrieved for viewing, the logged data is displayed as date and time stamped single line, tab delineated entries. Logged data can be retrieved in either hourly or daily blocks.

For permanent storage, the data logged by the WMS-16 can be copied to a magnetic disk. The format of the logged data has been designed to be compatible with most commercial spreadsheet software coma delineated (Excel, Lotus 1-2-3, and Quatro Pro among others).

The Control Module

The heart of the WMS-16 is the control module. The control module conditions and processes the signals generated by the attached sensors and outputs them via the RS-232 interface at a default rate of 9600 bits per second other bit rates are user selectable.

In addition to the RS-232 interface connector, connections are provided on the control module’s rear panel for all of the weather sensors.

Power is provided by an external 12V source, and the WMS- 16 comes equipped with a 12V wall transformer for powering the station from a standard 110V outlet. A 12V battery can be wired into the module to provide emergency power in the event of a loss of main power. This battery will provide backup power allowing data logging and output to continue uninterrupted. A fully charged 12V, 7 amp-hour battery will run the WMS-16 for three to four days.

Sensors

The standard sensors used with the WMS-16 have been designed to be rugged, compact, and light-weight. They interface directly to the control module without the need for additional signal conditioning. These sensors are accurate and reliable, and any combination can be used.

Wind

The wind sensor combines a three-cup anemometer and a wind vane on a single axis. The anemometer is a contact-type wind sensor which when rotated by the wind, triggers a series of momentary switch closures that are directly related to wind speed.

The wind vane uses a potentiometer to sense direction changes. Depending on the position of the potentiometer wiper, an analog voltage is output that corresponds to the position of the vane. By orienting the vane North (360°) during installation, wind can be easily calculated from the output voltage. The resolution of the wind vane is 1° (azimuth display), or 16 compass points (cardinal points display).