Browse Prior Art Database

Interference Switch

IP.com Disclosure Number: IPCOM000085307D
Original Publication Date: 1976-Mar-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Feldborg, JN: AUTHOR [+4]

Abstract

Spectrophotometers are known in which a probe is inserted into a liquid contained in a test tube, in order to measure optical characteristics of the liquid. Because of the relatively small sizes of test tubes, it is desirable, should the probe accidentally hit the tube, that the mechanism for moving the probe be stopped to prevent breakage.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 72% of the total text.

Page 1 of 2

Interference Switch

Spectrophotometers are known in which a probe is inserted into a liquid contained in a test tube, in order to measure optical characteristics of the liquid. Because of the relatively small sizes of test tubes, it is desirable, should the probe accidentally hit the tube, that the mechanism for moving the probe be stopped to prevent breakage.

Additionally, in some instances, the liquids themselves are volatile and create fumes that are of a highly volatile nature. Thus, in order to prevent any explosions, it is also desirable to limit sparking when such fumes exist, which sparking might be caused by the opening or closing of a switch.

Shown in the drawing is an explosion-proof switch designed to detect interference between a probe and a test tube, whereby the switch will be actuated so as to cause further movement of the probe to be stopped or inhibited.

As shown, the probe includes a rigid metallic sleeve 1, the lower end of which is connected to a mirror M that is illuminated by a light pipe within the sleeve 1 and reflects light back into the light pipe. The probe is designed to be inserted into a test tube for measuring the absorbance of liquid within the test tube. A conical contact 5 is mounted on sleeve 1 and cooperates with a stationary adjustable contact 6, mounted on the interior of a tube or housing 3 of a conductive material. The probe and housing are adapted to be connected by wires to a circuit for controlling the motion of the pro...