Electrical type temperature indicator

Electrical type temperature indicator:

Electrical temperature indicator is used to identify the changes occur in the temperature of a required medium, In this type of indicator unit it consist of an engine which has an insulated wire connected to the panel to obtain an exact temperature indication. by making all the connections perfect it is read to start, when we ON the switch the current used to supply through it, This current plays an main role to identify the temperature changes, when the engine temperature gets increased the current passing through it also increased by this the indicator also shows an increased temperature. 
 As in the some type of indicators when the temperature increases the current in the unit decreases. This indicates the increased temperature in the panel