MAGNETIC FIELD SENSOR (B)
(Ground Plane)
MODEL B-40
DESCRIPTION
The PRODYN Model B-40 sensor is a B-dot loop equivalent to the AFWL Model MGL-4. The sensor consists of a half-cylinder loop on a base plate that when mounted to a conducting surface, produces a voltage output in response to a time variant B field. This B-dot sensor can also be used to measure surface current density since the magnetic filed over a conductive sheet is related to surface current density (see Model B-S40 Data Sheet for equations).
This sensor is essentially one-half of a cylindrical loop with a gap structure located in the middle of each of its two quadrants. The voltage developed at the gaps are combined by a parallel-series wiring configuration that averages the signal over the loop structure. By this arrangement, signals induced by electric fields normal to the ground plane are cancelled out and a quarter-turn loop driving the output cable results. The pertinent equation for this device is:
® ®
Vo = Aeq . dB = sensor output (in volts)
dt
where
®
Aeq = sensor equivalent area (m2)
®
B = magnetic flux density vector (teslas)
The sensor is a passive device; therefore, an external power source is not required. The sensor is equipped for purging with a gas such as dry air, nitrogen or SF6. The sensor available with an axial output, Model B-40(A), or a radial output, Model B-40(R).
ELECTRICAL SPECIFICATIONS
Eqivalent Area (Aeq) . . . . . . . . . 1 x 10-2 m2
Frequency Response (3 dB Point) . . . > 230 MHz
Risetime (tr 10-90) . . . . . . . . . < 1.5 ns
Maximum Output (peak) . . . . . . . . ± 5 kV
Output Connector . . . . . . . . . . . 50 W GR-874**
PHYSICAL SPECIFICATIONS
ORDERING INFORMATION
* Customer to specify axial (A) or radial (R) version.
** This can be changed to a Type N, SMA, etc. (Max output voltage will be affected.)