AI 400 SERIES PROBES Page 55
C
YBER
A
MP
380, COPYRIGHT MARCH 2002, AXON INSTRUMENTS, INC.
When a SmartProbe is added to the system, it is common to re-start the data acquisition program to
force the program to re-read the probe memory.
Recommended Input Coupling
The instruction sheets for the individual AI 400 series probes contain recommendations concerning
the CyberAmp input configuration that should be used. For example, the recommendations for the
AI 401 differential amplifier probe are:
Positive input: DC or AC
Negative input: Ground
However, to invert the signal, the CyberAmp input coupling should be changed to:
Positive input: Ground
Negative input: DC or AC
The output of the AI 401 differential amplifier is a single-ended signal proportional to the difference
between the two input signals of the probe. This signal is connected to both the positive and negative
inputs of the CyberAmp. This allows the signal to be inverted by changing the input coupling of the
CyberAmp. The polarity of the signal from the AI 402 and AI 405 probes can also be switched by
changing the input coupling of the CyberAmp. Of course, one of the two differential CyberAmp
inputs must always be grounded.
The polarities custom SmartProbes may require that the main instrument must be set to record
differentially. For example, the internally generated temperature signal of a temperature transducer
adapter may actually be inversely proportional to temperature. Therefore, it is connected to the
negative input of the CyberAmp so that the signal seen by the operator is directly proportional to
temperature. The positive input is coupled to a DC voltage that compensates the measurement so that
it is 0 mV at 0°C. Hence, both inputs of the CyberAmp must be DC coupled to use this probe.
The memory chip in the probe should contain the recommended input coupling and low-pass filter
setting. This can be automatically read and used by the acquisition software.
Kommentare zu diesen Handbüchern