New Industry Products

Sulfur-Resistant Thin-Film Precision Resistors

April 12, 2016 by Jeff Shepard

Bourns, Inc. today announced its Model CRT-AS Sulfur-Resistant series of thin-film precision chip resistors. Designed specifically to operate in harsh environments exposed to high levels of sulfur contamination, the Bourns® Model CRT-AS series have a substantially increased lifespan compared to standard film resistors when exposed to a sulfurous gas environment, thus making them well-suited for a broad variety of mission-critical applications including industrial, automation, power supplies and communication base stations.

Many applications must operate in high-sulfur environments, such as where oils, lubricants, or fossil fuels are present, and in harsh, corrosive remote conditions and polluted industrial areas exhibiting high-sulfur contamination. The design of and materials used in typical thick film resistors, particularly the silver in the silver palladium internal terminal, make these resistors susceptible to the ingress of sulfur-based gasses. Common factors such as temperature, humidity and air flow, coupled with the presence of sulfur-based gasses, contribute to the corrosion process and the formation of harmful silver sulfide, which ultimately can cause an open circuit condition and failure of the resistor.

“As more and more devices and systems are connected, the reliable transfer of data and the need for uncorrupted data transmission and reception at the binary level is more important than ever. Any I/O interface failure, such as that from corrosion, can lead to a catastrophic system failure,” explained Brian Ahearne, Product Line Manager at Bourns, Inc. “Employing Bourns® sulfur-resistant film resistors help eliminate this type of corrosion-related hard failure which leads to improved system reliability and performance while reducing downtime.”

Available in four different footprints from 0402 (1005 Metric) up to 1206 (3015 Metric), the Bourns® Model CRT-AS series is manufactured using a thin-film element printed onto a ceramic substrate and tested in accordance with the ASTM B809-95 method. The series is also available in additional wide resistance, temperature coefficiency and tolerance options. The Bourns® Model CRT-AS series is available now and is RoHS compliant*. As a pricing reference, Model CRT0402-DZ is priced at $0.03 each in 10,000 piece quantities.