The measurement of meteorological variables is an international affair. The measurement method, instrument performance limits, calibration method and calibration traceability are as much as possible standardized.

See also calibration.

WMO used to make its own standards for meteorological instruments. Nowadays the official WMO policy is as much as possible to help prepare ISO standards that are also applicable to meteorology.

The measurements of wind speed, pressure, temperature, etc all are traceable to international standards. Specific meteorological measurements like visibility, present weather, surface condition are not yet standardized, (or we have not been able to find the appropriate standards). This essentially means that the manufacturer and buyer jointly take responsibility for the measurement method, the way in which it is calibrated, and the standard to which is compared.

To this date only solar radiation measurement has moved from a WMO standard to an ISO standard. ISO 9060.

Some vocabulary:

Primary standard: A standard that is designated or widely acknowledged as having the highest metrological qualities and and whose value is accepted without reference to other standards of the same quantity.

Secondary standard: A standard whose value is assigned by comparison to a primary standard of the same quantity.

Reference standard: A standard generally having the highest metrological quality available at a given location or in a given organization from which measurements made there are derived.

Working Standard: A standard that is used routinely to calibrate or to check material measures, measuring instruments or reference materials.

A working standard is generally checked against a reference standard.

Traceability: A property of the result of a measurement or the value of a standard whereby it can be related to stated references through an unbroken chain of comparisons all having stated uncertainties.

Calibration: The set of operations which establish, under specified conditions, the relationship between values indicated by a measurement instrument or measuring system, or values represented by a material measure, and the corresponding known values of a measurand.

Characterization: process of getting to understand instrument properties that affect the measurement accuracy.

Does anyone know more? Please write us, and we will adapt this page accordingly.