What are two merits of a thermoelectric thermometer and two merits of a constant volume gas thermometer?

Here are two merits for each type of thermometer:

a) Thermoelectric thermometer:
This type of thermometer has a very wide temperature range, capable of measuring extremely high and low temperatures. It also offers a fast response time to temperature changes due to its low thermal mass.

b) Constant volume gas thermometer:
This thermometer is considered a primary standard for temperature measurement due to its high accuracy and precision. Its readings are also largely independent of the specific gas used, making it highly reliable over a broad temperature range.