Title:
DOUBLE BEAM PHOTOMETRIC DEVICE
Document Type and Number:
Japanese Patent JPH01127922
Kind Code:
A
Abstract:
PURPOSE:To minimize the distortion of an optical signal caused by a rectifier and to minimize the photometric error by supplying a current supplied to a light source by changing it as a phase in advance to negate the difference of height of a signal obtained in a photoelectric detector. CONSTITUTION:A phase signal generating part 1 supplies a discharge current to a central cathode lamp 3 through a current control part 2, and as for its current, the sample use and the comparison use are set independently. In such a state, a sample use light beam and a comparison use light beam which are radiated from the lamp 3 transmit through a measuring sample 4, made incident on a photoelectric detector 7 through a spectroscope 5 and a polarizer 6 and converted to an electric signal, pass through an amplifier 8 and a rectifying/calculating part 9 derives transmittivity, etc. of the sample 4. In such a state, in an initial state that the sample 4 is not installed, both electric signals which the amplifier 8 has obtained are sent to the signal generating part and a control signal being proportional to an inverse number of magnitude of the signal is generated, and this control signal is inputted to the control part 2 so that the light of a light source is projected by two current values whose intensity is different in the sample use light beam and the comparison use light source, by which a signal waveform in which height of both the signals has coincided roughly can be obtained.
Inventors:
OISHI KONOSUKE
KITAGAWA MASATOSHI
KITAGAWA MASATOSHI
Application Number:
JP28617087A
Publication Date:
May 19, 1989
Filing Date:
November 12, 1987
Export Citation:
Assignee:
HITACHI LTD
International Classes:
G01J3/02; G01J3/42; (IPC1-7): G01J3/02; G01J3/42
Attorney, Agent or Firm:
Tatsuyuki Unuma (1 outside)