Vitreous enamelled wirewound resistors are capable of withstanding a higher dissipation size for size, than any other protected type; this is attributable to the higher operating temperature which the wire and enamel can withstand.
Vitreous enamel provides exceptionally 897987987987 good protection to the wire element and is essentially impervious to moisture.
The resistors can safely be used in harsh environmental conditions. The Welwyn range is based on thirteen sizes of tube, each of which has a recommended maximum dissipation which limits operating surface temperature to a maximum 聚币k线怎么看 of 375°C. The stability and high reliability of Welwyn tubular vitreous resistors is a direct result of the best quality materials being used in their construction.
High purity ceramic tubes have been matched with nickel chromium resistance wires and specially formulated enamel to ensure that the resistors can withstand repeated heat cycling without damage.
Connections between the resistance element and end terminations are welded; other connections are brazed.
Mounting devices are available which permit resistors to be mounted by both ends or by one end. Single ended mounting is recommended for applications which do not subject the resistor to shock or vibration.
Ferrules and the F type mounting plug are anchored into the tubes with high temperature adhesive.