AMETEK CTS
H-Field Test
Operating Manual
V 1.20
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1.4.
Current transformers
General setup for magnetic field
Two different current transformers are available:
- MFT 30 to generate continuous magnetic fields up to 30
A/m
- MFT 100 to generate continuous magnetic fields from 80
up to 100 A/m and short time magnetic fields up to 1000
A/m.
The transformers can be interchanged depending in which
range the operator has to test.
Please use always the attached original connection cables.
Your system was calibrated together with these cables and
the equivalent transformation factors are part of the software.
MFT 30
MFT 100
Using other components, the test setup shall be recalibrated and the equivalent factors shall be entered to the
software. Changing the test setup will require also a change of the factors (see para. 5.0 verification).
Magnetic field testing needs 230 V mains voltage for user with motor variac (variac NX1-260-16 / VAR 3005A-S16).
An external booster transformator (115 V to 230 V 10 kVA) is necessary for 115 V mains.
Transformer factor F
The given transformer factor is valid for short test up to one minute. For longer tests this factor will change, till the
system is in a stable temperature balance (10-20 minutes). Special higher currents are heating up the cables and
antenna. Therefore, the ohmic value of the cables and antenna increases during the test. The reason is the
heating caused by the high current. For longer application it can be necessary to readjust the voltage when the
temperature of the cable and antenna is stable.
1.4.1.
Measure the transformer and current factor
The test setup can be checked at the following measuring points.
Measuring points for H-field
verification
For verification the magnetic field please uses the following testpoints:
V1
Primary voltage magnetic field transformator
A2
Current in the antenna Loop (measured with a current transformer).
H1
H-field (measured with a H-field sensor).
Other measuring points, as shown in the figure above can be used for H-field measurements.
MFT xx
