Thermometer
A thermometer measures the extent of a given substance's hotness or coldness. Mercury is one of the liquids which is overly sensitive to temperature changes. The mercury expands and rises in the capillary tube when the substance to be measured is warm. Instead, mercury contracts. That is, principle of thermal expansion.
Thermograph
This tool records air temperature continuously on graphing paper during a period in a given area. It uses digital infrared imaging to record slight changes in temperature.
Mercurial Barometer
In a mercurial barometer, the atmospheric
pressure balances the mercury column, the
height of which can be measured precisely.
Corrections and adjustments are made for
temperature expansion of the instrument,
gravity and latitude in order to obtain
accurate measurements. Millibars,
millimeters, or inches of mercury are the
units of measurements of pressure readings.
Aneroid Barometer
A sealed box (blue, sometimes called an aneroid cell) is built around an aneroid barometer, which expands or contracts with increasing pressure. As it moves, it pulls or pushes a spring and a system of levers, moving a pointer up or down the dial yellow.
Barograph
A barograph is a recording barometer. The pen point that traces the pressure curve on the paper is made to move up or down by means of a series of levers attached to aneroid cells (metallic boxes) in tandem. The use of aneroid cells in tandem provide a more pronounced response to changes in atmospheric pressure than would be indicated by a single aneroid cell of the same size.
Sling Psychometer
A dry and wet-bulb thermometer is made of the sling psychrometer. The term bulb refers to the portion of the glass tube that contains mercury. In building the dry and the wet bulbs are exactly the same.
Hygrometer
This system uses an organic material (normally human hair) that expands and contracts as a result of the humidity around. This change can be made to move an indicator needle that moves across a scale, with graduations ranging from 0 to 100%.
8-inch Rain Gauge
An 8-inch rain gauge, so-called because the collector's inner diameter is exactly 8 inches above a funnel which leads rain into a cylindrical measuring tube or receiver. The collector's volume is 10 times that of the measuring tube. As a result, the actual precipitation depth is increased ten times when collected in a smaller measuring tube.
Tipping Bucket Rain Gauge
By capturing a small volume of water in one of two small buckets, the tipping bucket gauges act. Once the rain is caught, the tips of the bucket are empty. This tip is recorded and precipitation volumes and rates are transmitted as the number of tips and the rate at which they occurred.
Ceiling Light Projector
A projector with ceiling light project a small beam of light vertically onto a cloud foundation. The cloud base height is determined by using a clinometer positioned at a known distance from the projector to calculate the elevation angle contained on the cloud by the illuminated spot, the measurement, and the projector.
Ceiling Balloon
A ceiling balloon is a meteorological balloon whose rate of ascent has been predetermined. It is filled with gas lighter than air, usually hydrogen, and released. The time of release and the time the balloon disappears into the cloud are recorded. The time difference multiplied by the rate of ascent will give the height of the cloud base.
Pilot Balloon/Theodolite
• A Pilot Balloon is a weather balloon
lighter than air filled with gas. When
used in conjunction with a theodolite the
pilot balloon is used to determine wind
speed and direction at different
atmospheric levels.
Theodolite is similar to a transit
made by an engineer. It consists of
a sighting telescope mounted in
such a way that it is free to rotate
around a horizontal and vertical
axis and has graduated scales so
that the rotation angles may be
measured while tracking the pilot
balloon.
➢Radiosonde
The radiosonde is an airborne instrument used in the upper air for measuring sound, temperature, and relative humidity. A meteorological balloon inflated with hydrogen takes the instrument up aloft.
Rawin
Rawin is short for Radar and Wind. It is an electronic device that measures pressure, temperature and humidity
Wind Finding Radar
It determines the speed and direction of winds aloft by means of radar echoes. A radar target is attached to a balloon and it is this target that is tracked by ground radar. The bearing and time of interval of the echoes is evaluated by a receiver.
Weather Surveillance Radar
A Weather Surveillance Radar is of the long range type which detects and tracks typhoons and cloud masses at distance of 400 kilometers or less. This radar has a rotating antenna disk preferably mounted on top of a building free from any physical obstruction. Radio energy emitted by the transmitter and focused by the antenna shoots outward through the atmosphere in a narrow beam.
