Glossary of Terms

8bit 16bit resolution

In the decimal number system that we use in everyday life, numbers are represented using the digits 0 to 9. However computer data must be stored and processed as zeros and ones (binary system). The largest whole number that can be represented by 3 digits in the decimal system is 999. The largest whole number that can be represented by 3 digits in the binary system is 111 which is the same as 7 decimal.

We refer to the number of digits used in a computer binary number as the number of bits (from Binary digITs). If we use 8 bits in binary format the largest number we can have is 11111111 or 255 decimal. If we use 16 bits in binary the largest number we can have is 1111111111111111 or 65535 decimal. Processing and storing numbers in 16bit format uses more memory but gives us access to larger numbers. Processing and storing numbers in 8bit format uses less memory but gives us a much smaller number range.

In the Weather-Pro weather station the various sensors are read and converted in to digital data (Binary zeros and ones). This data can be stored in 8bit or 16bit format. If data is stored in 8bit format there is a maximum of only 255 steps from the smallest value that can be read to the largest value that can be read. The number of steps in a reading is referred to as resolution.

With 8bit resolution the readings are restricted to a maximum of 255 steps from smallest value to largest value. With 16bit resolution the readings are restricted to a maximum of 65535 steps from smallest value to largest value.

8bit format takes up less memory but has lower resolution

16bit format takes up more memory but has much higher resolution

Alarms

The Weather-Pro has a comprehensive alarm system. The user can set up to six alarm conditions that can trigger three different alarm modes either individually or in combination.

Anemometer

Instrument for measuring Wind Velocity

Auxiliary Input

The Weather-Pro has an Auxiliary Input for the connection of a Tipping Bucket Rain Gauge and one other sensor, such as Ground Temperature, Leaf Wetness, Ground Moisture or Water Level. The Weather-Pro Software displays readings from the auxiliary sensors along with the readings from the standard sensors. Auxiliary sensors are configured from the Main Menu - Control - Station Configuration option.

Auxiliary Probes

The probes that can be connected to the Weather-Pro Auxiliary Input. These include:

Pulse Output Sensors

Analog Output Sensors

These optional sensors are available from your Weather-Pro agent. These will be supplied with the auxiliary plug already connected. If you require a different length of cable than specified for the sensor please discuss this with your Weather-Pro agent.

The Weather-Pro tipping bucket rain gauge is fitted with an analog auxiliary input socket to allow for the connection of an analog output sensor. If you require both the tipping bucket rain gauge and an analog output sensor to be connected to the auxiliary socket on the cross arm, discuss this with your Weather-Pro agent before ordering.

To connect other sensors to the auxiliary input you will require a 4 pin male Switchcraft plug EN3C4M (Farnell part number 727-015). These can also be obtained from your Weather-Pro agent.

The auxiliary input pin out is as follows:

  1. Switched Power (3 volts at 2mA max used to energize sensors for 30ms before a reading is taken)
  2. Analog Input (0 to 3 volts)
  3. Slow Pulse input (usually used for tipping bucket rain gauge. Accepts a maximum pulse rate of up to 5 pulses per second with a minimum pulse duration of 1ms)

Ground (the common return for the Analog and Slow Pulse inputs)

Barometric Pressure

Another term for Air or Atmospheric Pressure. The weight that a column of atmospheric air exerts in a surface area. Barometric Pressure is measured in:

Date Time Range

A period of time specified by a Start date Time and a Finish Date Time. The Data Selector is used to select Date Time Ranges in the Weather-Pro Software.

Dew Point

The temperature at which the relative humidity would reach 100% and dew would form.

Disease Prediction

The Weather-Pro software can be configured to monitor meteorologic conditions that could lead to the rapid growth of specific bacterial and fungal populations. The software can therefore be used to predict the growth of these populations. This can be a useful tool in the planning of spraying cycles and pest management.

Leaf Wetness

A percentage index indicating the relative wetness of a typical leaf. This wetness is the result of humidity and precipitation.

Light Energy

The energy produced by the sun and measured at the Light Energy sensor. This includes not only the energy from visible light but also energy from the infrared and ultraviolet areas of the spectrum either side of the visible light. The accumulated light energy can be used as a indication of the amount of photosynthesis that plants can perform in a given time period.

Logging Interval

The time between successive weather station data loggings. At the beginning of each logging interval the station takes all relevant readings and stores them in memory. On the Weather-Pro the Logging Interval can be set from 1 min to 10 hours in 1 min steps.

Relative Humidity

The measure of amount of moisture held by the air expressed as a ratio of the total amount of water that the air could hold . As Air Temperature increases the amount of water that the air can hold also increases so the Relative Humidity is very temperature dependent. For a given amount of moisture in a given volume of air, the Relative Humidity will decrease as the temperature increases. The term is usually used to distinguish the readings from Absolute Humidity which is a measure of the actual amount of moisture in a given volume of air and is usually measured in millimeters of water per cubic meter of air.

RJ11

Electronics Industry name given to the small plug used on the serial communications cable of the Weather-Pro

RS232

Strictly speaking, RS232 is an electrical specification for a serial communication system. It usually refers to the serial port of a computer or other device such as the Weather-Pro weather station

RS485

Strictly speaking, RS485 is an electrical specification for a serial communication system. The Weather-Pro Plus weather station uses an RS485 link to collect readings from remote sensors.

Sample

A set of readings from a number of channels, all taken at the same Date Time

Sensor Calibration

The process of testing sensors and adjusting the convertion of the sensor readings so that the sensors give an accurate result. With the Weather-Pro your sensors are factory calibrated. If you require any replacement or auxiliary sensors, thses will be supplied with calibration figures. These calibration figures will usually be an offset and gain that must be entered in to the Sensor Calibration page accessed from Control Menu option.

Slow Pulse Input

The auxiliary input used for the connection of a Tipping Bucket Rain Gauge. The input can accept a maximum pulse rate of up to 5 pulses per second with a minimum pulse duration of 1ms).

Solar Radiation Shield

The solar radiation shield houses the temperature, humidity and pressure sensors. Fins on the shield encourage air flow through the housing so that the temperature, humidity and pressure sensors are kept at air temperature and are not warmed by direct exposure to solar radiation.

Station Identity

The name that the user gives a Weather-Pro weather station. This name is programmed in to the weather station. It can be up to 60 characters in length and can include spaces.

Tadiran
Units
Wind Chill Factor

When air moves over an object, energy (temperature) is transfered to the moving air and therefore lost from the object. The faster the air moves the more energy (temperature) is lost. This loss of temperature with air speed is referred to as Wind Chill

Wind Vane

Instrument used to measure the direction of the wind. The Weather-Pro weather station has been designed to be mounted with the wind vane end of the cross arm pointing true north in the northern hemisphere and tru south in the southern hemisphere.