Mercury is the traditional fluid used for thermometers and other indicating instruments. Its properties are well-known and understood. Some published test methods specify use of mercury-filled thermometers, but many of these standards are being revised to avoid problems related to its use.
Please check your state and local ordinances controlling mercury instruments before ordering. Regulations are constantly changing and Gilson may not be permitted to ship these devices to you.
Most ASTM and AASHTO test methods now permit non-mercury alternatives for temperature measurement, and our Technical staff can help you select digital or non-mercury glass thermometers to meet published test methods.