How to differentiate between bimetallic thermometer model WSS and WSSX?

WSS series bimetallic thermometer is a kind of measurement in the field of low temperature test instrument. Can be directly measured in the process of various production - 80 ℃ ~ + 500 ℃ within the scope of vapor and liquid gas medium temperature. Has the following characteristics: the scene display temperature, intuitive and convenient; Safe and reliable, long life; Core pulling type maintenance or replacement movement didn't stop a short time. Type axial and radial type, universal type, variety complete, suitable for all kinds of the needs of the installation. WSSX said electric contact bimetallic thermometer, electric contact bimetallic thermometer is based on the ring around the made of bent bimetallic strip. Side heated expands, turns the pointer, the instrument will show should value, and prevent environmental vibration in double metal internal filling or double metal part shows some separation and measurement to achieve seismic effect. Electric contact bimetallic thermometer is the use of lead contact changes when temperature changes, when contact with the upper and lower limits or disconnected at the same time, make the circuit of relay action, to call the police.