SAAS 52MM EGT EXHAUST GAS TEMPERATURE PYRO METER PYROMETER SAAS SG21240 GUAGE is used to monitor the exhaust gas temperature (EGT) of turbo equipped vehicles in conjunction with a pyrometer probe. EGT is an indication of how hot the combustion process is in a vehicles cylinders. Excessive EGT can cause engine or turbocharger damage. Many conditions can result in excessive EGT (i.e. too much fuel or not enough air) and are made worse when a vehicle is pulling a heavy load, climbing or running at continuous high speeds.