85RF Fluke Electronics, 85RF Datasheet - Page 59
85RF
Manufacturer Part Number
85RF
Description
PROBE HIGH FREQ 500MHZ
Manufacturer
Fluke Electronics
Type
High Frequencyr
Specifications of 85RF
Impedance
10M Ohm
Voltage - Max
30VRMS, 200VDC
Lead Free Status / RoHS Status
Lead free by exemption / RoHS compliant by exemption
Ratings
-
Current Rating
-
Color
-
Termination
-
Wire Insulation Material
-
Cable Length
-
Other names
532457
The ac input voltages are divided with the same divider arrangement as the
dc input voltages, with the exception that the 2V ac voltage range is divided
by 10. The divider output signals for ac voltages are ac-coupled to the input
of a true rms ac converter which produces a current output. A negative dc
representation of the ac input signal is filtered and applied to the input of the
a/d converter.
3-7.
Current measurements are made using a double-fuse-protected, switchable,
five-terminal current shunt (0.1 ohm, 1 ohm, 10 ohm, 100 ohm or 1 kilohm)
to perform the current-to-voltage conversion required by the a/d converter. A
block diagram of current measurements is shown in Figure 3-5. When the dc
current function is selected, the dc voltage drop across the shunt is filtered
and applied to the input of the a/d converter. When the ac current function is
selected the ac voltage drop across the shunt is ac-coupled to the input of the
true rms ac converter. The dc representation of the ac voltage is filtered and
applied to the input of the a/d converter. All current ranges use the 200 mV
a/d converter input range.
*Integrator gain in a/d converter reduced by factor of 10.
DC Voltage
AC Voltage
Function
Current Measurement
200 mV
200 mV
1000V*
Range
750V*
200V
200V
20V
20V
2V*
2V
Table 3-1. Voltage Input Divider
Divider
1/1000
1/1000
1/1000
1/1000
1/100
1/100
Input
1/10
1/1
1/1
1/1
Range of A/D Converter Input
0 to -2V (-0.75V max. input)
-2V to + 2V (1V max. input)
-200 mV to +200 mV
-200 mV to +200 mV
-200 mV to +200 mV
Functional Description
Theory of Operation
0 to -200 mV
0 to -200 mV
0 to -200 mV
0 to -200 mV
-2V to +2V
3
3-9