New Caledonia Exports of hydrometers, thermometers, pyrometers, barometers, hygrometers to Tonga was US$396 during 2013, according to the United Nations COMTRADE database on international trade. New Caledonia Exports of hydrometers, thermometers, pyrometers, barometers, hygrometers to Tonga - data, historical chart and statistics - was last updated on June of 2024.