DI-8B47 Linearized Thermocouple Input Modules
FEATURES
Interfaces to Types J, K and T
Linearizes Thermocouple Signal
High Level Voltage Outputs
1500Vrms Transformer Isolation
ANSI/IEEE C37.90.1
Input Protected to 240VAC Continu-
ous
120dB CMR
70dB NMR at 60Hz
Low Drift with Ambient Temperature
Accurate CJC -40°C to +85°C
CSA, FM, and CE Certifications
Pending
Mix and Match Module Types
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-8B47 module
isolates, filters, amplifies, and linearizes a
single channel of temperature input from
a thermocouple and provides an analog
voltage output.
Linearization is accomplished using a four
breakpoint piecewise linear approximation.
The DI-8B47 can interface to industry
standard thermocouple type J, K, and T and
has an output signal of 0V to +5V. Each
module is cold-junction compensated to
correct for parasitic thermocouples formed
by the thermocouple wire and screw termi-
nals on the mounting backpanel. Upscale
open thermocouple detect is provided by
an internal pull-up resistor.
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.
A special input circuit on the DI-8B47
module provides protection against ac-
cidental connection of power-line voltages
up to 240VAC.
The modules are designed for installation
in Class I, Division 2 hazardous locations
and have a high level of immunity to envi-
ronmental noise.
SPECIFICATIONS
Typical at T
A
= +25oC and +5V Power
DI-8B47
-0.1V to +0.5V
-25nA
Input Range
Input Bias Current
Input Resistance
Normal
Power Off
Overload
50M
450k
450k
Input Protection
Continuous
Transient
240VAC
ANSI/IEEE C37.90.1
0.25mA
±0.02C/Ω1
1500Vrms max
ANSI/IEEE C37.90.1
120dB
70dB at 60Hz
See Ordering Information on Page 2
Sensor Excitation Current
Lead Resistance Effect
CMV, Input to Output
Transient, Input to Output
CMR (50Hz or 60Hz)
NMR
Accuracy
Stability
Offset
Gain
±20ppm/oC
±75ppm/oC
Noise
Output, 100kHz
250μVrms
3Hz
150ms
0 to +5V
Bandwidth, -3dB
Response Time, 90% Span
Output Range
Output Protection
Transient
Continuous Short to Ground
ANSI/IEEE C37.90.1
Cold Junction Compensation
Accuracy, 25oC
Accuracy, -40oC to +85oC
Power Supply Voltage
Power Supply Current
Power Supply Sensitivity
Mechanical Dimensions
±0.5oC
±1.5oC
+5VDC ±5%
30mA
±25ppm/%
1.11" × 1.65" × 0.40"
(28.1mm × 41.9mm × 10.2mm)
Environmental
Operating Temperature
Storage Temperature
Relative Humidity
-40oC to +85oC
-40oC to +85oC
0 to 95% Noncondensing
DATAQ Instruments, Inc. 241 Springside Drive Akron, Ohio 44333 Tel: 330-668-1444 Email: support@dataq.com www.dataq.com