• logic-input control of peak capture, unlatching of latched limit conditions,
application of tare offset, and initiation of hard-copy printout
For complete specifications, see Appendix A.
1.b.2 THE MODEL 3510 THERMOCOUPLE CONDITIONER
This instrument accepts a temperature signal from a Type B, E, J, K, R, S, or T
Thermocouple. The sensor may be grounded or ungrounded. The conditioner
employs "absolute" calibration, which means that no calibration is required by the
user, once the proper "TC Type" is entered. During operation, appropriate refer-
ence-junction compensation, digital linearization, and engineering-unit scaling are
automatically applied. Detection of "open" thermocouples is also provided.
The 3510’s special rear connector assembly contains a thermistor for precise
measurement of the reference-junction temperature. Therefore, no external cold
junction is required—although the user may supply his own Controlled Ambient
Temperature Zone for reference-junction purposes, if desired.
1.b.3 THE MODEL 3530 LVDT CONDITIONER
This instrument measures displacement, force, pressure, and other parameters
obtained with a 5- or 7-wire linear variable differential transformer (LVDT)
capable of 3280-Hz operation and having primary impedance of 80 Ωor greater.
It can also be used with a 3- or 5-wire variable reluctance transducer. The
"normal" input range can be 0-150, 0-300, or 0-600 mV/V, full scale. Input provi-
sions also exist for "long-stroke" LVDT's (0-1, 0-2, or 0-4 V/V, full scale). Nominal 3
V-AC (rms) excitation is supplied.
1.b.4 THE MODEL 3540 FREQUENCY INPUT CONDITIONER
This instrument is used for measurement of flow, rpm, and other phenomena that
can be sensed by pulse transformer transducers with two-wire isolated windings
(tachometer pickups, turbine flowmeters, etc.), transistor or logic-circuit drivers,
"zero-velocity" (true digital output) sensors, and similar frequency-generating
transducers. It will accept any AC or unipolar pulse signal, floating or grounded,
irrespective of waveform. Input range is from 10% to 100% of 250, 500, 1000,
2000, 4000, 8000, 16000, or 32000 Hz.
The 3540’s analog-input threshold level is selectable to accommodate signals
from 100 mV to 100 V, thus guaranteeing reliable triggering when the input is at
the low end of the frequency range. Capacitive coupling of 0.1 µF is provided for
low-frequency inputs, to eliminate false triggering by signal noise or any DC offset
that exists for the frequency signal. For "zero-velocity" sensors, an excitation of
nominal ±5 V-DC ± 5% is supplied.
When you know the manufacturer-supplied full-scale rating of the frequency
source (or the highest frequency expected to be measured), the Model 3540’s
measurement channel can be quickly calibrated by issuing an "FRQ" command
through the RS-232/485 Interface Port.
1.2
1
INTRODUCTION
1.b GENERAL INSTRUMENT DESCRIPTIONS