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FULL CLIMATE STATION - GUIDANCE NOTE

Full Climate Station – Guidance on instruments required

A Full Climate Station (FCS) should have the following equipment as standard:

ItemHP-II Specification No.**

  1. Stevenson Screen30.011
  2. Raingauge, non-recording30.004
  3. Raingauge, Automatic siphon30.005
  4. Liquid in glass thermometers (four required)30.008
  5. Sunshine recorder30.007
  6. Counter type anemometer30.002
  7. Wind direction indicator30.003
  8. Evaporimeter, US Class A Pan 30.012

In addition, two recording devices may be purchased, although these are optional items:

  1. Thermograph, bimetallic type30.009
  2. Hygrograph, hair string type30.010

** See website:

Specifications are available for all these instruments apart from the Stevenson Screen, where approval for the specification still appears to be pending for some reason. However, as the current specification conforms to IMD norms, it is recommended that the present Pending Specification, 30.011, be accepted unchanged.

30.011 in fact specifies two screens, a standard width one, and a double width one. A standardwidth screen is suitable for the four thermometers only, but if a thermograph and hygrograph are required, then a double width screen would be required. Note that a single instrument can in fact be purchased, a thermo-hygrograph, which records both temperature and relative humidity, and this would probably fit into a standard width screen. The Stevenson screen should be mounted with the roof approximately 1.8 to 2 m above ground level so that with the doors open, the instruments are at eye level as far as possible.

For item 4, thermometers, four are required:

  1. A mercury in glass thermometer capable of recording maximum temperature in a day;
  2. A mercury or alcohol in glass thermometer to record minimum temperature;
  3. A dry bulb thermometer (normally mercury in glass) and;
  4. A wet bulb thermometer (again normally mercury in glass). Afabric wick covers the bulb of the thermometer with the bottom of the wick attached to a water reservoir.

The measuring range of all thermometers should be -35oC to +55oC.

The optional thermograph (30.009) is a simple temperature recording device, and the hygrograph (30.010) is a simple device to record relative humidity. Neither device is mandatory, as the appropriate information is available from the manually read thermometer records.

The sunshine recorder (30.007) should be mounted on a brick or concrete pillar at a height of between 1 to 1.4 m so that recording cards are at a convenient height for the observer.

The anemometer (30.002) must be mounted on a pole with the cups at a height of exactly 2 m. The wind direction indicator (30.003) should also be mounted on a pole at approximately 2 m. Note that the recording height of the cup anemometer must be at 2 m exactly (+/- perhaps 30-50mm), but the wind direction indicator height is not particularly important.

Frank Farquharson

TAMC Hydrometeorology a Hydrology Data Analysis Specialist

18th November 2009

HP II
Created on 28/11/2018
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