Table of Contents
Advertisement
Chapter 6, COMPUTER OPERATION
NHZ.
ENBW[.]
NN[.]
DEFEQU [n
6-18
and ADC1 is the value that would be returned by the ADC1 command. The response
range is -3000 to +2079
In floating point mode, the LR. command reports a number equivalent to
log(X/ADC1). The response range is -3.000 to +2.079
Causes the lock-in amplifier to respond with the square root of the noise spectral
density measured at the Y channel output, expressed in volt/Hz or amps/Hz
referred to the input. This measurement assumes that the Y channel output is
Gaussian with zero mean. (Section 3.3.16). The command is only available in
floating point mode.
Equivalent noise bandwidth
In fixed point mode, reports the equivalent noise bandwidth of the output low-pass
filters at the current time constant setting in microhertz.
In floating point mode, reports the equivalent noise bandwidth of the output low-pass
filters at the current time constant setting in hertz.
Noise output
In fixed point mode causes the lock-in amplifier to respond with the mean absolute
value of the Y channel output in the range 0 to 12000, full-scale being 10000. If the
mean value of the Y channel output is zero, this is a measure of the output noise.
In floating point mode causes the lock-in amplifier to respond in volts.
n
n
n
n
n
]
1
2
3
4
5
6
The DEFEQU command is used to define the user equations, which take the
following form:
(A
B)
Equation =
D
Parameter n
is used to specify the equation to be modified, and is either 1 for
1
Equation 1 or 2 for Equation 2.
Parameter n
is used to set the addition/subtraction operator in the numerator
3
according to the following table:-
n
Operator
3
0
Subtraction
1
Addition
The parameters n
, n
, n
2
4
according to the following table:
n
Variable
0
X or X1
1
Y or Y1
2
MAG or MAG1
3
PHA or PHA1
4
ADC1
5
ADC2
6
ADC3
7
ADC4
8
C1
Define user equation
C
and n
specify the variables A, B, C and D respectively
5
6
Range
±30000
±30000
0 to 30000
±18000
±10000
±10000
±10000
±10000
0 to 100000
Advertisement
Table of Contents
