Ametek 7230 Instruction Manual page 77

RATIO
+7.5
+2.5
0
-2.5
-7.5
Log ratio
When set to Log ratio the corresponding DAC connector on the rear panel of the
instrument outputs a voltage related to the Log ratio calculation, which is defined
as follows:-



LOG RATIO log
10

where X output is the X channel output as a percentage of the full-scale
sensitivity and 1 is the voltage (expressed in volts) applied to the ADC 1 input
connector on the rear panel of the instrument. Hence, for example, if the
instrument were measuring a 100 mV signal when set to the 500 mV sensitivity
setting, the X1 channel output were maximized and a 1 V signal were applied to
the ADC1 input, then the value of Log ratio would be:-




LOG RATIO log
10


LOG RATIO = 0.301
The relationship between the voltage at the DAC connector and the Log ratio
value is defined as follows:-
Log ratio
+2.000
0
-3.000
Note: If Ratio < 0 then Log ratio = -3.000
Equation 1
When set to Equation 1 the corresponding DAC connector on the rear panel of
the instrument outputs a voltage related to Equation 1, which is defined using the
Output Equations panel, as follows:-
Equation 1
+10000
0
-10000
Equation 2
When set to Equation 2 the corresponding DAC connector on the rear panel of
the instrument outputs a voltage related to Equation 2, which is defined using the
Output Equations panel, as follows:-
Chapter 5, WEB CONTROL PANEL OPERATION
DAC Voltage
7.5 V
2.5 V
0.0 V
-2.5 V
-7.5 V


10 X output


ADC1 input

0.1

10

0.5

1.000


DAC Voltage
2.000 V
0.0 V
-3.000 V
DAC Voltage
10.0 V
0.0 V
-10.0 V
5-35