Iwatsu SY-8218 Instruction Manual page 46


6-3: To understand the meaning of the target parameter and Tolerance, it is necessary to understand the measurement process of this
product.
The measurement process of this product is explained referring to Fig.6-3 which indicates the measurement process specifying
Max. magnetic field Hm as a target parameter, setting Tolerancex [%], and using the horizontal axis as time.
Magnetic field
磁界
H
Tolerance
x [%]
Setting value of
目標パラメ－タ
target parameter
の設定値
H
m
Approx. value excitation period
0
When measurement starts, this product gradually increases the signal output and excites a sample while observing a peak
value of the magnetic field H.
And then, when H exceeds a specified setting value Hm, this product makes the 1st measurement while keeping the excitation
status. The period after starting the excitation until H exceeds Hm is called an approx. value excitation period.
If H obtained in the 1st measurement is within the range of
magnetization is reduced from the sample so that any residual magnetization is not left, and the measured value is displayed. If
H is not within the range, the signal output is changed so that H can approach to Hm while exciting the sample.
In this period, the 2nd measurement is made and the same processing as the 1st measurement is done. This period is called
Gradual approach excitation period.
That is, until the specified value of the target parameter become within the setting Tolerance, this product repeats measurement
while changing the signal output.
The upper limit number of retries is set by Retry on Configuration screen.
If a measurement result is not within a setting Tolerance after measurement is repeated by the number of Retry times, the
warning message "W60: Retry over!" is displayed and the last measurement result after reduced magnetization is displayed.
As Tolerance becomes small, the measurement time increases, resulting in rising in a sample temperature. Therefore, care
should be taken.
1st measurement
1回目の測定

x H

m
H
m
100
概値励磁期間
Fig.6-3 Measurement process
2nd measurement
2回目の測定
Gradual approach excitation period
漸近励磁期間

x H

H
m
100
34
B-H ANALYZER SY-8218 / SY-8219
3rd measurement
3回目の測定
(measurement value
(測定値表示)
displayed)
Reduced excitation period
減磁期間
Excitation period
, the measurement finishes at that time,
m
ｔ
励磁時間