Pair of electrodes for detecting acidity or basicity of oil

• US 6,549,015 B2
• Filed: 12/14/2000
• Issued: 04/15/2003
• Est. Priority Date: 12/14/1999
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation, Nippon Soken, Inc.
• Original Assignee: DENSO Corporation
• Inventors: Ueda, Hiroshi, Teramoto, Hayaki, Yoshida, Takahiko, Asami, Kazushi, Horie, Kazuyuki, Nonoyama, Tatsuhiko, Naito, Kiwamu
• Primary Examiner(s): Le, N.
• Assistant Examiner(s): Deb, Anjan K.
• Application Number:
  US09/735,460
• Publication Number:
  US 20010005137A1
• Time in Patent Office: 852 Days
• Field of Search: 324/438, 324/698, 324/444, 324/71.1, 204/435, 204/433, 204/196.38, 204/292, 436/163, 205/775, 205/787.5
• US Class Current: 324/438
• CPC Class Codes: G01N 33/2876 Total acid number

Abstract

In a pair of electrodes where a potential difference is changed in accordance with acidity or basicity of oil, a reference electrode is made of cobalt or a cobalt alloy, and a sensitive electrode is made of tungsten or a tungsten alloy. The sensitive electrode is used in combination with the reference electrode. Accordingly, it is possible to provide a pair of electrodes for detecting the acidity or the basicity of the oil which use a novel electrode material not hazardous to the environment and at the same time, suited for use in a semiconductor fabrication technique.

Claims

1. A pair of electrodes for detecting acidity or basicity of oil, the pair of electrodes are constructed by

a reference electrode made of cobalt or a cobalt alloy;

and

a sensitive electrode made of tungsten or a tungsten alloy, the sensitive electrode being used in combination with the reference electrode,

wherein a potential difference between the sensitive electrode and the reference electrode is changed in accordance with the acidity or the basicity of the oil.

2. A reference electrode used in combination with a sensitive electrode, for a pair of electrodes where a potential difference is changed in accordance with acidity or basicity of oil, wherein the reference electrode is made cobalt or a cobalt alloy.

3. The reference electrode according to claim 2, wherein:

the sensitive electrode combined with the reference electrode is made of titanium or a titanium alloy;

the sensitive electrode has an oxide film on the surface thereof; and

a thickness of the oxide film is in a range of 7-80 nm.

4. The reference electrode according to claim 2, wherein

the sensitive electrode combined with the reference electrode is made of tungsten or a tungsten alloy.

5. A sensitive electrode used in combination with a reference electrode, for a pair of electrodes where a potential difference is changed in accordance with acidity or basicity of oil, wherein:

the sensitive electrode is made of titanium or a titanium alloy;

the sensitive electrode has an oxide film on the surface thereof; and

a thickness of the oxide film is in a range of 7-80 nm.

6. A detecting device for detecting acidity or basicity of oil, the device comprising:

a first electrode made of one of cobalt and a cobalt alloy; and

a second electrode made of one of tungsten and a tungsten alloy, the second electrode being used in combination with the first electrode,

wherein a potential difference between the first electrode and the second electrode is changed in accordance with the acidity or the basicity of the oil.