1.0 GENERAL INFORMATION
The
504 two-wire transmitter takes in millivolt signals, provides
amplification, common-mode isolation, and controls the current
drawn from a 9-to-50 V dc source to produce the 4-to-20 mA output
signal.
Common-mode voltage between the input and the output circuits
is tested at 1500 V rms. As much as 750 ohms dropping resistance
may be used in the power leads when the unit is energized from
a 24 V dc source because of the small compliance voltage needed
by the unit. Accidental overloads of over one minute by 120 V
rms on either input or output leads do not damage the 504.
1.1 ACCURACY AND STABILITY
Selected resistors in a temperature-sensing output
bridge provide cancellation of both input and output Span temperature
effects. High-ambient-temperature compensation points are checked.
The unit is certified for accuracy from -40 to +85°C (-40
to +185°F).
1.2 ADAPTABILITY/TURNDOWN
The
Span of the 504 can be ranged anywhere from 5 to 100 mV by selection
of one of four jumper positions, with fine tuning provided by
a multiturn, top-accessible potentiometer. Sixteen Zero steps,
also provided by 504 jumpers, allow placement of the input for
4-mA output zero at an input anywhere from -30 to +60 mV, with
fine tuning provided by another top-accessible, multiturn potentiometer.
This 504 turndown capability exceeds that of any other known transmitter.
1.3
LINEARITY
The 504 zero suppression capabilities (high turndown ratio) allow
high-gain control for continuous processes with good linearity
for many nonlinear transducers when small span is selected.
1.4 ELECTRICAL ISOLATION
504 input (and shield) and output (DC power) barrier
strips accept wires up to two mm in diameter (13 gauge), and are
mechanically isolated from each other to prevent input/output
wiring contact during installation.
1.5 SHOCK RESISTANCE
Lightweight 504 circuit boards are formed into a rigid
box structure and firmly soldered and epoxied to the case top.
The circuit-board box is doubly coated with RTV silicone for environmental
protection. When installed in the rugged, die-cast case, the 504
can withstand the shock of a 6-foot drop onto a hard surface (although
scarring of the case and/or deformation of the plastic cover can
occur).
1.6 WATERPROOF/RFI-RESISTANT CASE
The 504 case is made from Zamac (zinc alloy), coated
with polyurethane, and gasketed with fluorosilicone. Fluorosilicone
plugs protect the top-access Span and Zero potentiometers.
1.7 MOUNTING ADAPTABILITY
The small size of the 504 (less than 75 mm or 3 in
OD) permits mounting in many small spaces, including explosion-proof
housings for wiring compatability with other equipment in hazardous
environments. A bulkhead adaptor provides for wall-mounting. A
snaptrack adaptor mounts on either American or European relay
tracks. Tapped holes in the case rear provide for custom mounting
on any surface, indoor or out. An optional opaque top cover shields
the barrier strips from exposed environments.
2.0 SPECIFICATIONS
2.1 INPUT
Configuration:
Isolated, mV input, mA output
Input impedance: 100 megohms
Lead resistance: Up to 1k ohms for specified performance
Common mode voltage, input to case: Test, 2100 V peak;
IEC spacing for 354 V peak
Common mode rejection, input to case: 100 dB min at 60
Hz
Overvoltage protection: 120 V ac max/1 min exposure
2.2 OUTPUT
Linear
range: 4 mA to 20 mA dc
Compliance (supply-voltage range): 9 to 50 V dc
Overvoltage protection: 120 V ac
Reverse polarity protection: 400 V peak
Common mode voltage, output to case: 1500 V ac max
Common mode rejection, output to case: 100 dB min at
60 Hz
2.3 ACCURACY
Hysteresis
and repeatability: Within 10 uV ©+0.1% of Span
Six month stability: Within 10 uV ©+0.2% of
base input
Power supply effect: Within ±0.005%/V
Ambient temperature effect
Zero Error: ±0.04 °C/°C Typical
Span: ±0.03 °C/°C Typical
2.4 ENVIRONMENTAL
Operating
temperature: -40º to 85°C
Storage temperature: -55 to 125°C
Humidity: Waterproof
Vibration: 1.52 mm (.06 in) double amplitude, 10-80
Hz cycled
Shock: 55g, half-sine, 9-13 msec duration, 6' drop
to hard surface
Watertight pressure limit: 35 kPa (5 psi)
Mounting position: Any
2.5 MECHANICAL
Case
material: Zamac (zinc alloy), polyurethane-coated, fluorosilicone-gasketed
Weight: 300 g (10 oz)
Diameter: 74 mm (2.9 in)
Height (including barriers): 52 mm (2.1 in)
Connections: #6 screws with wire clamps
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