This document discusses several common hydrometeorological instruments: 1. Anemometers, which measure wind speed and direction. Common types are cup anemometers, windmill anemometers, and ultrasonic anemometers. 2. Barometers, which measure atmospheric pressure and can indicate changes in weather patterns. 3. Hygrometers, which detect and measure humidity through various operating principles like hair tension or capacitive sensors. 4. Rain gauges, which measure precipitation. Common types are non-recording gauges and recording gauges like weighing bucket, tipping bucket, or floating/natural syphon gauges.

1. HYDROMETEOROLOGICAL
INSTRUMENTS
Presented by: ENGR. JEAH A. BEJARASCO

3. ANEMOMETER
 are meteorological devices sed to measure wind
speeds and can commonly be found in weather
stations. Today, except in weather stations, they
are widely used in determining the average speed
in ventilation systems built in the industrial and
residential buildings.

4. ANEMOMETER
1. Cup Anemometers
TYPES OF ANEMOMETER
 Also known as rotational anemometers cup
anemometers
 simplest types of anemometers and have been
around for a very long time.
 As wind presses against these
cups, the arms at the top
rotate around the central pole.

5. ANEMOMETER
2. Windmill Anemometers
TYPES OF ANEMOMETER
 able to determine the direction of the wind as
they have a propeller that is attached to the front
of the device with a tail section behind, on the
same axis as the propeller on a central pole.
 involves sonic pulses to measure the velocity of
the wind. The device sends sonic pulses across a
path to sensors located across which are able to
sense the incoming pulses..
3. Ultrasonic

6. BAROMETER
 measures atmospheric pressure. Changes
in atmospheric pressure are most often
caused by the rise of warm air and the
descent of cold air
Barometric pressure changes with local
weather. Rising pressure means fair weather
while falling pressure means poor weather.

7. HYGROMETER
Hygrometer is a device used for detecting and
measuring humidity. There are several types of
hygrometers (coil, hair tension, capacitive, resistive
and others), whose operation is based on different
principles.

8. Rain Gauge
A rain gauge is an instrument for measuring the
precipitation that has fallen in a given time interval.
The rain gauge is part of every weather station. It is
used in meteorology as an additional tool of the
weather forecast and the climatology for the purpose
of long-term statistics of precipitation.
The amounts of rain accumulated in the gauge are
read either manually or by automatic weather station
(AWS).

9. Types of Rain Gauge
1. Non-Recording Type Rain Gauge
Non-recording type rain gauge is most common type of rain gauge used by
meteorological department. It consists of a cylindrical vessel 127mm in diameter with a
base enlarged to 210mm diameter.
At its top section, funnel is provided with circular brass rim which is 127mm exactly so
that it can fit into vessel well. This funnel shank is inserted in the neck of a receiving
bottle which is 75 to 100mm high from the base section and thinner than the cylinder,
placed into it to receive rainfall.

10. Types of Rain Gauge
1. Recording Type Rain Gauge
There are three types of recording rain gauges
a) Weighing bucket type
b) Tipping bucket type
c) Floating or natural syphon type rain gauge

11. Types of Rain Gauge
1. Recording Type Rain Gauge
There are three types of recording rain gauges
a) Weighing bucket type
b) Tipping bucket type
c) Floating or natural syphon type rain gauge