Tegam 1750 - Reference Current Modes

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INSTRUMENT DESCRIPTION
REFERENCE CURRENT MODES
There are several types of pulses available for making measurements. Below is a summary of
characteristics for each type of trigger mode and the sequence of events that occur during an actual
measurement.
+
REF
0 A
SAMPLE
SAMPLESAMPLE
SAMPLE
SAMPLES FOR HIGH AND LOW STATES ARE TAKEN
FOR 32 CYCLES, THEN A READING IS PROCESSED.
THE PROCESS IS REPEATED CONTINUOUSLY.
READING COMPLETE
+ REF
0 A
SAMPLE
SAMPLE
SAMPLE
SAMPLE
CONTINUOUS SAMPLES ARE TAKEN FOR 32 CYCLES,
THEN A READING IS PROCESSED
READING COMPLETE
+ REF
0 A
- REF
A
A
A
A
ACB
B
B
B
B
C
C
CD D
SAMPLE
COMPLETE READING
SAMPLE
COMPLETE READING
SAMPLE
SAMPLE
+ REF
0 A
- REF
A
A
CB
B C D
SAMPLE
COMPLETE READING
SAMPLE
+ REF
0 A
- REF
A
A B
B
C
C D
SAMPLE
COMPLETE READING
SAMPLE
Fast Continuous:
Readings are taken towards the end of each +REF/ 0A state.
The test signal is an alternating reference current from + REF
to 0A, with automatic thermal and noise rejection.
Fast One-Shot:
This mode must receive an external trigger and is a shortened
version of the Fast Continuous mode. A total of 64 data
samples are taken. 32 samples on + cycles and 32 samples
on the 0 Ampere cycles. These samples are digitally processed
to produce reading
Delayed Continuous:
Continuous Alternating reference current from + REF to
– REF.
“A” represents the programmable delay time from 1 to 250 mS.
“B” represents the line cycle time
- 1/f (Sampled Input for Line
Cycle
Integration)
“C” is the time required for broken lead detection to take place
“D” is when the reading is processed and updated
.
Delayed One-Shot
Alternating reference current from + REF to
–
REF.
Triggering via GPIB, RS232 or rear trigger input will cause a
single cycle of reference current.
Delayed One-Shot
(Triggered Via Front Panel)
Alternating reference current from + REF to
–
REF.
Triggering via the front panel. Once triggered, two reference
cycles are released of which the latter pulse will be used to
take the actual reading.