| 摘要 |
PURPOSE:To eliminate the need for the control operation at the time of zero- point correction by measuring a low-concentration reference plate and a high- concentration reference plate whose concentration reference values are already known at the time of the zero-point correction. CONSTITUTION:When a power switch 12 is turned on, a zero-point measurement mode is entered and a switch 14 for zero-point correction is turned on to start measurement. Then signals outputted by photodetectors 26 and 28 are sent to logarithmic converting amplifiers 30 and 31, and amplified and converted logarithmically. The output signals of the amplifiers 30 and 31 are processed by subtraction 32 to obtain a concentration signal. This signal is A/D-converted 33 and converted into measurement data at a specific period. This data obtained by the conversion is inputted to a CPU 34 and stored 35. This CPU 34 performs sequence control over the operations of respective parts according to a program stored in the memory 35. Further, a battery check circuit 40 detects the voltage of a battery 38 and sends a warning signal to the CPU 34 when the voltage drops below a constant voltage. Thus, the measured value of the body 22 to be measured is corrected by using the zero-point correction data, so the need for adjustment operation is eliminated and the zero-point correction is facilitated. |
