This Regulations is enacted in accordance with the terms in Paragraph 6 of Article 20, Meteorological Act.

The Central Weather Bureau （hereinafter referred to as CWB）of the Ministry of Transportation and Communications
（hereinafter referred to as MOTC）, the laboratory accredited by the Chinese National Laboratory Accreditation, or the
laboratory accredited by a cross-recognized foreign country（hereinafter either of the three laboratories aforementioned is
referred to as the Calibration Unit）, may accept the application of an exclusive observation station to calibrate its equipped
observation instruments according to Paragraph 1 of Article 20, Meteorological Act.

The standard for calibration of observation instruments shall trace to the standard of the National Laboratory of Weights and
Measures Standard, Bureau of Standards, Metrology, and Inspection, Ministry of Economic Affairs, or the national standard of
a cross-recognized foreign country; the calibration cycle of observation instruments shall follow the rules of the individual
Calibration Unit.
The preceding rules of calibration shall be enacted separately.

An exclusive observation station shall follow a self-decided calibration cycle of each equipped observation instrument and
apply for an instrument calibration from a Calibration Unit to prove it be qualified for use, and then can be used.
The error of an observation instrument is within the tolerant error as listed in the attached “Criteria for accreditation of the
observation instruments” shall be considered as qualified.（see attached tables）
The difference between the displayed value of the observation instrument under calibration and the standard value of the
standard device is named the error of that observation instrument; the tolerant errors settled for each type of observation
instruments are named the maximum permissible errors.

Should the observation instrument(s) of an exclusive observation station shows an error caused by natural disaster or other
causes, an application for calibration from a Calibration Unit is needed.

Should the CWB find that the observation record of a certain observation instrument of an exclusive observation station had
successive or obvious errors, CWB may inform that station to stop using that instrument and order to send it for calibration.

An exclusive observation station shall fill in an application form and turn in a calibration fee when applying for a calibration of
its equipped observation instrument.
When apply for a calibration from the CWB, the calibration fee shall be charged in accordance with the provisions enacted by
the MOTC according to Paragraph 2 of Article 30, Meteorological Act.
When apply for a calibration from a Calibration Unit other than the CWB, the calibration fee shall be charged in accordance
with the provisions enacted by that unit.

The calibration of observation instrument(s) shall be conducted at a Calibration Unit; whereas the Calibration Unit may send its
faculties to its place to conduct an in-situ calibration upon the request and application of the exclusive observation station under
at least one of the following conditions:
1.Too big to move;
2.Adhered to the ground, a building, or other mechanic equipment and hard to tear apart;
3.It’s liable to be damaged or lose its accuracy while moving or other considerations.
For applying to the CWB for a calibration, the applicant shall not only turn in the application fee (stipulated fees) in accordance
with Paragraph 2 of Article 30, but also pay for the errand costs (including transportation fees), overhead fees, and/or other
necessary expenditures.

The observation instrument sent for calibration shall bear marks of the brand of production or factory logo, serial number of
production, engraved scale, and the vernier (if any); the attached technical document or brochures shall also be submitted for
calibration’s reference.
Auto-recording types of instrument for calibration shall be submitted with its recording or displaying device(s); power supply
exclusively used for the instrument shall be sent together.

Should the observation instrument sent for calibration is totally damaged, seriously contaminated, or not useable, the
Calibration Unit might reject the application.

The Calibration Unit may tear apart or ask the applicant to tear apart the instrument for partial calibration, if necessary.

If the instrument sent for calibration with two (2) or more scales and any one of them fails to meet the criteria, the whole
instrument shall be considered as a failed one.

The Calibration Unit shall issue a certificate to those instruments that passed the calibration, or a notice to those stations with
instruments failed to pass the calibration.

The format of the application form, certificate, and notice aforementioned in this Regulations shall be determined by the
Calibration Unit.

This Regulations shall become effective on the date of promulgation.
Criteria for accreditation of the observation instruments

A. Atmospheric Pressure Measuring Instrument
Unit : hectopascal（Symbol : hPa）
Types of InstrumentMeasuring Range Maximum Permissible Error
Precision Mercurial
Barometer866~1050hPa
（650~787mmHg）±0.33hPa
（±0.25mmHg）
Fortin-type Mercurial
Barometer866~1050hPa
（650~787mmHg）±0.67hPa
（±0.5mmHg）
Aneroid Barometer866~1050hPa
（650~787mmHg）±0.67hPa
（±0.5mmHg）
Aneroid Barograph866~1050hPa
（650~787mmHg）±1.33hPa
（±1.0mmHg）
Electronic Barometer866~1050hPa
（650~787mmHg）±0.67hPa
（±0.5mmHg）



B. Temperature Measuring Instrument
Unit : degree Celsius（Symbol : ℃）
Types of InstrumentMinimal Scale/Name Measuring Range（℃） Maximum Permissible Error （℃）





Glass-tube

Thermometer






nterval
≦1/5℃－50~－20 ± 0.5
痋?0 ~100 ± 0.3
nterval
≧1/2℃－20 ~＋40 ± 0.3
?0~100 ± 0.5
hermometer
in Iron Tube≦－20 ± 0.5
痋?0 ± 0.3
aximum
Thermometer＜0 ± 0.5
~ 50 ± 0.3
inimum
Thermometer＜－40 ± 1.0
?0 ~－20 ± 0.5
痋?0 ± 0.3
Metallic
ThermometerThermograph －20 ~＋40 ± 0.5
hermometer ± 0.5
Electronic
ThermometerThermograph －20 ~＋40 ± 0.5
hermometer ± 0.5



C. Humidity Measuring Instrument
Unit：percentage （Symbol：% RH）
Types of InstrumentMeasuring Range
（% RH）Maximum Permissible
Error （% RH）
Hygrometer and/or
Hygrograph0 ~ 100 ± 5





D. Precipitation Measuring Instrument
Unit：milli-meter （Symbol：mm）
Types of InstrumentMaximum Permissible Error（%）
Rain Gage± 0.3
Tipping-bucket Rain GagePrecipitation ± 3





E. Wind-direction Measuring Instrument
Unit：degree
Types of InstrumentMeasuring Range
（degree）Maximum Permissible
Error（degree）
Anemometer
or
Anemometrograph
0 ~ 360
± 5


F. Wind-speed Measuring Instrument
Unit：meter per second （Symbol：m/s）
Types of InstrumentMaximum Permissible
Error（%）
Propeller-type
Anemometer/Anemometrograph± 5
Three/four cup-type
Anemometer/Anemometrograph± 5


G. Sunshine-duration Measuring Instrument
Unit：hours （Symbol：h）
a. Minimum threshold：120W/m2
b. Maximum Permissible Error：± 0.1h


H. Solar-radiation Measuring Instrument
Unit：watts per square meter （Symbol：W/m2）
Maximum Permissible Error：± 5%