DI-8B35 Linearized 4-Wire RTD Input Modules
FEATURES
SPECIFICATIONS
Typical at T = +25ºC and +5V Power
A
• Interfaces to 100Ω Platinum RTDs
DI-8B35
• Linearizes RTD Signal
Input Range Limits
Input Resistance
-200˚C to +850˚C (100Ω Pt)
• High Level Voltage Outputs
• 1500Vrms Transformer Isolation
Normal
Power Off
Overload
50MΩ
200kΩ
200kΩ
• ANSI/IEEE C37.90.1 Transient Pro-
tection
Input Protection
• Input Protected to 240VAC Continu-
ous
Continuous¹
Transient
240VAC
ANSI/IEEE C37.90.1
• 120dB CMR
Sensor Excitation Current
Lead Resistance Effect
CMV, Input to Output
Transient, Input to Output
CMR (50Hz or 60Hz)
NMR
0.25mA
±0.001˚C/Ω²
• 70dB NMR at 60Hz
• Low Drift with Ambient Temperature
1500Vrms max
ANSI/IEEE C37.90.1
120dB
• CSA, FM and CE Certifications
Pending
• Mix and Match Module Types
70dB at 60Hz
Accuracy³
DI-8B35-01
DI-8B35-02
DI-8B35-03
DI-8B35-04
±0.20˚C
±0.15˚C
±0.20˚C
±0.45˚C
DESCRIPTION
DI-8B modules are an optimal solution
for monitoring real-world process signals
and providing high level signals to a data
acquisition system. Each DI-8B35 module
isolates, filters, amplifies, and linearizes a
single channel of temperature input from
an RTD and provides an analog voltage
output.
Stability
Output Offset
Gain
±20ppm/ºC
±50ppm/ºC
Noise
Output, 100kHz
250µVrms
3Hz
Bandwidth, -3dB
Response Time, 90% Span
Output Range
150ms
RTD excitation is provided from the
module using a precision current source.
Excitation current does not flow in the
input signal leads, which allows RTD mea-
surements to be made independent of lead
resistance. The exciation currents are small
(0.25mA) which minimizes self-heating of
the RTD.
0 to +5V
Output Protection
Continuous Short to Ground
ANSI/IEEE C37.90.1
Transient
Power Supply Voltage
Power Supply Current
Power Supply Sensitivity
Mechanical Dimensions
+5VDC ±5%
30mA
±25ppm/%
1.11" × 1.65" × 0.40"
(28.1mm × 41.9mm × 10.2mm)
Signal filtering is accomplished with a
three-pole filter optimized for time and
frequency response which provides 70dB
of normal-mode-rejection at 60Hz. One
pole of this filter is on the field side of the
isolation barrier for anti-aliasing, and the
other two are on the system side.
Environmental
Operating Temperature
Storage Temperature
Relative Humidity
-40ºC to +85ºC
-40ºC to +85ºC
0 to 95% Noncondensing
¹240VAC between + and - -/+EXC/-EXC terminals. 120VAC between - and +EXC/-
EXC terminals and between +EXC and -EXC terminals.
A special input circuit on the DI-8B35
module provides protection against ac-
cidental connection of power-line voltages
up to 240VAC. Clamp circuits on the I/O
and power terminals protect against harm-
ful transients.
²Ω refers to the resistance in one lead.
³Includes conformity, hysteresis and repeatability.
The modules are designed for installation
in Class I, Division 2 hazardous locations
and have a high level of immunity to envi-
ronmental noise.
DATAQ Instruments, Inc.
• 241 Springside Drive • Akron, Ohio 44333 • Tel: 330-668-1444 • Email: support@dataq.com • www.dataq.com