Testo 608-H2 Hygrometer 70 °C, ±2 %RH Accuracy, 50 °C Max, 98 %RH Max, UKAS

Accurately measure relative air humidity, temperature and dewpoint with this digital hygrometer from Testo. The device has a large liquid-crystal display (LCD) screen to show measured values clearly, and an LED (light-emitting diode) alarm signal alerts you to conditions that require immediate attention so you can react quickly. It's powered by a 9V battery that has a one-year lifespan, so you can use it for a long time before you need to replace the battery. This also means it's portable and simple to use as it doesn't need to be connected to an external power source.

• Quick measuring rate of 18 seconds for accurate real-time measurements

• Chemical laboratories

A hygrometer measures condensation by passing a current between two plates to test capacitance, which is the ability of an item to retain an electrical charge. As the presence of water increases, the capacitance also increases, allowing the hygrometer to gauge the moisture level.