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5 Measuring with the NBM-550 and HF probes
44
NBM-550
Narda
5.1
Avoiding measurement errors
The measurement result can be falsified by external
influences when measuring electromagnetic fields.
Considerable measurement deviations can occur under
certain circumstances, particularly when measuring low
field strengths. The following tips may be of assistance in
recognizing sources of interference so as to avoid
measurement errors. The following factors can affect the
measurement result:
•
Electrostatic charges
•
Changes in temperature
•
Strong low frequency fields (e.g. due to high tension
lines)
Electrostatic charges
The following effect will be noted with all field strength
meters: If you move the probe quickly, excessive field
strength values will be displayed which do not reflect the
actual field conditions. This effect is caused by electrostatic
charges.
The NBM has been designed in a way that minimizes this
effect. However, if you move the probe very quickly, field
strengths on the order of a few V/m can be displayed.
Recommendation:
Hold the device steady during the measurement. Delete the
stored maximum values and average values by pressing
Clear
before using the
Max
,
Average
or
Max Average
result types. Do not touch the probe at any time during the
measurement.
Changes in temperature
Ambient temperature changes as well as warming by direct
sunlight will create offset voltages that may impact the
measurement result. Zeroing eliminates offset voltages
within the instrument only. Offset voltages caused by the
probe or the probe connector can not be eliminated.
Particularly probes with thermocouple sensors are affected
by offset voltages until stable temperature conditions are
achieved.
Содержание NBM-550
Страница 10: ...Contents VIII NBM 550 Narda ...
Страница 38: ...3 Preparing the NBM 550 for use 28 NBM 550 Narda ...
Страница 52: ...4 Getting started 42 NBM 550 Narda ...
Страница 88: ...6 Measurements with the NBM 550 and EHP 50 78 NBM 550 Narda ...
Страница 110: ...9 PC software 100 NBM 550 Narda ...
Страница 139: ...12 10 CE Declaration of Conformity Narda NBM 550 129 12 10 CE Declaration of Conformity ...
Страница 140: ...12 Specifications 130 NBM 550 Narda ...
Страница 141: ...12 11 Declarations of origin Narda NBM 550 131 12 11 Declarations of origin NBM 550 Germany EHP 50 Italy ...
Страница 142: ...12 Specifications 132 NBM 550 Narda ...
Страница 146: ...13 Ordering information 136 NBM 550 Narda ...
Страница 147: ...Narda NBM 550 137 14 Glossary This chapter explains some important terms that are used in this operating manual ...
Страница 154: ...Index 144 NBM 550 Narda ...
Страница 155: ......