Skip to main content

ESA Data Ontology

Search from vocabulary

Content language

Concept information

Instruments > In Situ/Laboratory Instruments > Temperature/Humidity Sensors > CLH2

Preferred term

CLH2  

Definition

  • The University of Colorado Closed-path Laser Hygrometer, version 2 (CLH2) is an infrared absorption instrument designed to measure so-called “total water”, the sum of water vapor and particulate water. It is a second-generation sensor that derives from the original CLH, which has been flown on the NASA DC-8 and WB-57F and the NSF/NCAR G-V and C-130 [Hallar et al., 2004; Davis et al., 2007a; 2007b]. This version of the instrument uses a fiber-coupled tunable diode laser at 1.37 µm to measure by absorption the water vapor resulting from the evaporation of cloud particles. The spectrometer will be housed in a modified PMS canister and coupled to a heated forward-facing inlet. Sampling of particles is deliberately sub-isokinetic, which results in enhancements of particle mass relative to ambient by factors ranging between 30 and 70. Therefore, condensed water even in very thin clouds can be measured with high precision and accuracy. (en)

Broader concept

Change note

  • 2021-03-01 16:27:13.0 [sritz] Insert Concept add broader relation (CLH2 [ae8cab2b-3bd1-47ea-b160-97dc6b31f306,560898] - Temperature/Humidity Sensors [bb5a51d9-0ded-40ed-9bfd-7cb0e788f1a5,545515]);
  • 2021-03-01 16:28:01.0 [sritz] insert AltLabel (id: null category: primary text: Total Water Instrument: Closed-path Laser Hygrometer 2 language code: en); insert Definition (id: null text: The University of Colorado Closed-path Laser Hygrometer, version 2 (CLH2) is an infrared absorption instrument designed to measure so-called “total water”, the sum of water vapor and particulate water. It is a second-generation sensor that derives from the original CLH, which has been flown on the NASA DC-8 and WB-57F and the NSF/NCAR G-V and C-130 [Hallar et al., 2004; Davis et al., 2007a; 2007b]. This version of the instrument uses a fiber-coupled tunable diode laser at 1.37 µm to measure by absorption the water vapor resulting from the evaporation of cloud particles. The spectrometer will be housed in a modified PMS canister and coupled to a heated forward-facing inlet. Sampling of particles is deliberately sub-isokinetic, which results in enhancements of particle mass relative to ambient by factors ranging between 30 and 70. Therefore, condensed water even in very thin clouds can be measured with high precision and accuracy. language code: en);
  • 2021-03-01 16:28:45.0 [sritz] update Definition (https://www2.acom.ucar.edu/sites/default/files/seac4rs/UniversityOfColoradoTotalWaterInstrument.pdf);

URI

https://gcmd.earthdata.nasa.gov/kms/concept/ae8cab2b-3bd1-47ea-b160-97dc6b31f306

Download this concept:

RDF/XML TURTLE JSON-LD Last modified 12/6/20