Medical thermometer and displaying temperature became available, electronic thermometers (often called "digital", because they display numeric values) have been used. Many display readings to great precision (0.1 °C or 0.2 °F, sometimes half that), but this should not be taken as a guarantee of accuracy: specified accuracy must be checked in documentation and maintained by periodical recalibration. A typical inexpensive electronic ear thermometer for home use has a displayed resolution of 0.1 °C, but a stated accuracy within ±0.2 °C (±0.35 °F) when new. The first electronic clinical thermometer, invented in 1954, used a flexible probe that contained a Carboloy thermistor. Types
IbpB thermometer has been removed. IbpB thermometer The IbpB thermometer is an RNA thermometer element found in the "ibpAB" operon. The operon contains two heat-shock genes, encoding inclusion body binding proteins A and B (IbpA/B), and is the most drastically upregulated operon under heat-shock in "Escherichia coli". "IbpA" is regulated by a ROSE element found in its 5' UTR, while "IbpB" has its own heat-sensitive cis-regulatory element. The activity of this thermoregulator was confirmed "in vitro" but was not found "in vivo", suggesting more complicated operon regulation exists in bacterial cells. The IbpB protein, whose expression is regulated by the IbpB thermometer,