Altek 334A Manual page 3

Operating instructions
Source milliamps
mA OUT, % OUT (Percent of 4 to 20 mA)
Choose this function to provide an output from 0.00 to 24.00
milliamps. The compliance voltage is a nominal 24 VDC to provide
the driving power to your milliamp receivers.
1) Disconnect one or both input wires from the device to be
calibrated.
2) Move the slide switch to mA or % 4 to 20 mA and move the left
hand toggle switch to SOURCE.
3) Connect the red SOURCE lead of the calibrator to the plus (+)
input of the device and the black SOURCE lead to the minus (-).
Output current is adjusted by turning the knob. Span and Zero
outputs are available by moving the QUIK-CHEK switch to recall
20.00 & 4.00 mA.
Simulate 2-wire transmitters
2-WR mA, 2-WR % (Percent of 4 to 20 mA)
Choose this function to simulate a 2-wire transmitter output from
0.00 to 24.00 milliamps. Operates in loops with power supply
voltages from 3 to 100 VDC.
1) Disconnect one or both input wires from the device to be
calibrated.
2) Move the slide switch to mA or % 4 to 20 mA and move the left
hand toggle switch to 2 WIRE TRANSMITTER SIMULATOR.
3) Connect the red lead of the calibrator to the plus (+) input of the
field connections and the black lead to the minus (-)
Loop current is adjusted by turning the knob. Span and Zero
outputs are available by moving the QUIK-CHEK switch to recall
20.00 & 4.00 mA.
Receiver 12.00
(Powers external
2-Wire Transmitter)
Power Supply
2 to 45 VDC
Read DC Volts
READ V
Choose this function to measure from -99.99 to +99.99V DC.
1) Move the slide switch to READ VDC and move the left hand toggle switch to READ.
2) Connect the red (+) and black (-) lead leads across the voltage to be measured
Any DC Voltage from -99.99 to +99.99 Volts may be measured. Loop power supplies,
signal voltages at receivers, batteries and trasnmitter voltage drops may be
measured. Signals exceeding ±100 VDC will be indicated by OVRLD on the LCD.
Milliamp Receiver Input
Controller
Transmitter
Computer
Logger
I/P
DCS
To
Sensor
+ I N - REF +OUT-
Typical
2-Wire
Transmitter
(Disconnected)
Read milliamp outputs
READ mA, READ % (Percent of 4 to 20 mA)
Choose this function to measure from 0.00 to +52.00 milliamps or -
25.0 to 300.0%.
1) Open the current loop at any convenient point along the signal
path
2) Move the slide switch to mA or % 4 to 20 mA and move the left
hand toggle switch to READ.
3) Connect the red READ (+) lead of the calibrator to the more
positive point of the break and the black READ (-) lead to the
more negative
Signals below 0 mA or open circuits are indicated by 0.00 mA
(-25.0%) on the display. Signals above 52 mA are current limited
by protection circuitry to approximately 55.00 mA.
Power & measure 2-wire transmitters
mA OUT, % OUT (Percent of 4 to 20 mA)
Choose this function to simultaneously supply power to a 2-wire
transmitter while displaying the 4-20 mA output of the transmitter.
1) Disconnect one or both input wires from the 2-wire transmitter to
be calibrated
2) Move the slide switch to mA or % 4 to 20 mA and move the left
hand toggle switch to SOURCE.
3) Turn the knob clockwise several times until full scale output
(24.00 mA/125.0%) is obtained (this can be verified by cliping
the outputs leads together and checking that the display
indicates 24.00 mA/125.0%).
4) Connect the red SOURCE lead of the calibrator to the plus (+)
input of the device and the black SOURCE lead to the minus (-)
5) Connect a sensor or calibrator to the input of the 2-wire
transmitter
Model 334A supplies a nominal 24 Volts DC at 24 mA to the 2-
Wire transmitter. The current passed by the transmitter will be
accurately displayed by the 334A.
+ I N -
Transmitter Input
Sensor
Transmitter
Process Signal
Simulated Input
24.00
Milliamp Output Signal
Controller
Transmitter
P/I
DCS
REF +OUT-
33.4
Typical
2-Wire
Voltage to be Measured
Loop Power Supply
Transmitter Voltage Drop
Battery
1 to 5 Volt Loops