The CL-355A is a small, lightweight, portable dry block calibrator, that offers fast heat-up and cooldown times with excellent performance specifications at a wide operating temperature range. It’s a good choice for standard bench lab work or as a portable field unit. The unit covers the temperature range from 5°C (9ºF) above ambient up to 400°C (752ºF) using a large multi-well machined aluminum insert block as the heat transfer medium to the sensors under test. The CL-355A uses the same aluminum inserts as the CL-740A calibrator. This calibrator is designed to work safely under the following conditions: ambient temperature range: 5 to 40°C (9 to 104°F), up to 95% relative humidity, non-condensing.