Inquiry (采购产品): letter Ms. Sandra Peterson, General Manager Muth Associates, Inc. 53 Progress Avenue. Springfield, MA. 01104-3230 Dear Madam: I am contacting you to introduce myself and Comus International. We have been in the switch and sensor market for over 30 years and have also been manufacturing reed switch based proximity sensors. We have recently added to our sensor line the inductive and capacitive sensors. We have a high quality product with very competitive pricing and it would be my pleasure to quote in the very near future. INDUCTIVES: The sensor consists of an induction loop. Electric current generates a magnetic field which collapses, generating a current that falls asymptotically toward zero from its initial level when the input electricity ceases. The inductance of the loop changes according to the material inside it and since metals are much more effective inductors than other materials, the presence of metal increases the current flowing through the loop. This change can be detected by sensing circuitry which can signal some other device whenever metal is detected. PROXIMITY/REED SWITCHES: The reed switch contains two ferromagnetic blades which have end portions separated by a small gap when the switch is open. The reeds are hermetically sealed in opposite ends of a tubular glass envelope. A magnetic field (from an electromagnet or a permanent magnet) will cause the contacts to pull together, thus completing an electrical circuit. The stiffness of the reeds causes them to separate and open the circuit when the magnetic field ceases. Another configuration contains a non-ferrous, normally-closed contact that opens when the ferrous normally-open contact closes. Good electrical contact is assured by plating a thin layer of precious metal over the flat contact portions of the reeds. I am looking forward to hearing from you and invite you to visit our web site, www.comus-intl.com to view our complete product line. Sincerely, John Rollo Vice President **** Hidden Message ***** John Rollo 01012 USA Company: Comus International E-mail: jrollo@comus-intl.com **** Hidden Message ***** jrollo@comus-intl.com
