3-2
5
RELATIVE / OUTPUT.
When REL is selected, the meter will establish the present field level as the “new”
zero point. This feature is useful for measuring field changes relative to a field level other than zero.
Model 4190 only: By pressing SHIFT- REL, the analog output is activated and a DC or AC signal
proportional to the field magnitude will be available at the analog output 3.5mm connector. The 4100
Series does not respond to DC fields, but a DC analog voltage output proportional to the field level is
available and may be more easily connected to a data acquisition system or other equipment. Calibration
is set to 2.0 Vdc full scale when the analog output is set to the DC mode ( OUT--- ). If the meter is
operating on the low range then 2.0Vdc will correspond to 200mG or 20µT. If the meter is operating on
the high range, then 2.0Vdc will correspond to 2000mG or 200µT. For example, 1.32Vdc could represent
either 132.0mG or 1320mG depending which range the meter is on. The output when set to AC mode
will be a time-varying signal which will allow the user to view the waveform on an oscilloscope if desired.
The AC output is calibrated to 1.0VacRMS full scale and follows the typical frequency response curve as
shown in Fig. 3.5. Just like the DC mode, the AC output signal voltage may represent different field
levels depending on whether the meter is operating in low or high range.
Meter Ports
Figure 3-2
6
USB Connector.
The meter can be connected to a PC via the USB 2.0 port. The 4190 can perform
Data logging and be commanded through this port with the 4190 application software. Remote
automation can also be performed through this port. The 4100 may also be powered from the +5 volt line
of the USB connector, thus drawing its power from the computer to which it is attached.
7
Analog Output Connector. (4190 only)
A voltage signal representative of the magnetic flux density
being measured is available at this connector which accepts a standard 3.5mm 2-conductor plug as
commonly used in audio applications. The sleeve contact of the connector is circuit ground and the
analog output signal is the tip contact. Loading of the output by any external equipment should be10 k
Ω
minimum to prevent erroneous readings.
8
External Power Connector.
The 4100 series accepts a 5 volt DC power supply wall adapter for power.
This optional adapter is available from OECO. Please call for pricing (part number 115003). Use of any
other adapter could damage the meter and void the warranty.
Powering the 4100 with multiple sources:
The 4100 can obtain power from any of 3 sources: batteries, USB
port, or external AC adapter connected to the External power connector. If more than one of these sources is
connected simultaneously, the power will be drawn from whichever source has the highest voltage. For example
if the voltage of the 4 batteries totals 4.8 volts and the USB is connected (which has 5.0 volts) the power will be
drawn from the USB port instead of the batteries. However if new batteries are at 6.0 volts, power would be
drawn from them rather than the USB port which is only 5.0 volts.
