Lake Shore Model 475 Gaussmeter User’s Manual
Probes and Accessories
7-9
7.6
HELMHOLTZ COIL LOW FIELD STANDARDS
Lake Shore offers three Helmholtz coils: 2.5-, 6-, and 12-inch diameter. Check the Lake Shore website for any recent
additions to this line.
These coils are accurately calibrated using field standards maintained at Lake Shore. Most standards are traceable to
physical standards such as a coil of carefully controlled dimensions, or in some cases, to proton resonance. The field
strengths are measured on the basis of the field generated by a current through the coil.
When combined with a customer-supplied power supply, these coils can be used as low-field reference magnets to
complement our set of standard reference magnets (defined in Paragraph 7.7). To achieve maximum field, the power
supply must be capable of 2 A output and a constant-current mode is recommended.
MH-2.5
MH-6
MH-12
Inside Diameter
2.5 inches
6 inches
12 inches
Field Accuracy
±0.5%
Field Strength
≈
30 G @ 1 A
≈
25 G @ 1 A
≈
13 G @ 1 A
Field Homogeneity
0.5% within a cylindrical
volume 0.75" long,
0.75" diameter, located
at center of coil
0.5% within a cylindrical
volume 1.6" long,
1.6" diameter, located
at center of coil
0.5% within a cylindrical
volume 3.2" long,
3.2" diameter, located
at center of coil
Coil Resistance/Inductance
≈
3
Ω
/6.3 mH
≈
10
Ω
/36 mH
≈
20
Ω
/93 mH
Maximum Continuous Current
2 A DC or AC RMS
Operating Temperature Range
10 to 40
°
C (50 to 104 °F)
Helmholtz_2.bmp
Figure 7-13. Model MH-2.5 Helmholtz Coil
Содержание 475
Страница 16: ...Lake Shore Model 475 Gaussmeter User s Manual 1 6 Introduction 1 4 SAFETY SYMBOLS ...
Страница 25: ...Lake Shore Model 475 Gaussmeter User s Manual Background 2 9 Figure 2 8 Examples of PI Control ...
Страница 36: ...Lake Shore Model 475 Gaussmeter User s Manual 3 10 Installation This Page Intentionally Left Blank ...
Страница 68: ...Lake Shore Model 475 Gaussmeter User s Manual 4 32 Operation This Page Intentionally Left Blank ...
Страница 82: ...Lake Shore Model 475 Gaussmeter User s Manual 6 6 Remote Operation Figure 6 2 Model 475 Status System ...