Product Highlights
View Prices
Datasheet, Manual, etc.
Videos and Multimedia
Guides and Cool Stuff
Software Options
Articles and Support

Product Highlights

• Interfaces to 100Ω Platinum, 10Ω Copper, or 120Ω Nickel RTDs
• True 4-Wire Input
• Linearizes RTD Signal
• High Level Voltage Output
• 1500 VRMS Transformer Isolation
• ANSI/IEEE C37.90.1-1989 Transient Protection
• Input Protected to 240VAC Continuous
• 160dB CMR
• 95dB NMR at 60Hz, 90dB at 50Hz
• CSA Certified

In RTD temperature measurement applications requiring a very high level of accuracy, the DI-5B35 4-wire RTD input module offers a significant advantage over 3-wire measurement techniques. The DI-5B35 measures only the voltage dropped across the RTD and almost completely ignores the resistance or length of the RTD lead wires. The DI-5B34 3-wire RTD module provides lead resistance compensation, but requires equal lead resistances, while the DI-5B35 does not require matched lead resistances.

Each DI-5B35 module provides a single channel of RTD input which is filtered, isolated, amplified, linearized, and converted to a high level analog voltage output. This voltage output is logic switch controlled, which allows these modules to share a common analog bus without the requirement of external multiplexers.

The DI-5B35 module is designed with a completely isolated computer side circuit which can be floated to ±50V from power common (pin 16). This complete isolation means that no connection is required between I/O common and power common for proper operation of the output switch.

RTD excitation is provided from the module by a precision current source. The excitation current is available on two leads which are separate from the two input signal measuring leads. The excitation current does not flow in the input signal leads, which allows RTD measurements to be totally independent of lead resistance. The excitation current is very small (0.25mA for 100Ω Platinum and 120Ω Nickel, and 1.0mA for 10Ω Copper) which minimizes self-heating of the RTD.

Signal filtering is accomplished with a six-pole filter which provides 95dB of normal-mode rejection at 60Hz and 90dB at 50Hz. Two poles of this filter are on the field side of the isolation barrier, and the other four are on the computer side. After the initial field-side filtering, the input signal is chopped by a proprietary chopper circuit. Isolation is provided by transformer coupling, again using a proprietary technique to suppress transmission of common mode spikes or surges. The module is powered from +5VDC, ±5%.

A special input circuit on the DI-5B35 provides protection against accidental connection of power-line voltages up to 240VAC.

Want to port your data into a spreadsheet or a database?

Check out our add-on software:

Ordering Information, Models, and Prices

Part Number	Description	Price (US)	DATAQ Store
100Ω Platinum, α = 0.00385
DI-5B35-01	-100°C to +100°C (-148°F to +212°F)	$205	Quantity:
DI-5B35-02	0°C to +100°C (32°F to +212°F)	$205	Quantity:
DI-5B35-03	0°C to +200°C (32°F to +392°F)	$205	Quantity:
DI-5B35-04	0°C to +600°C (32°F to +1112°F)	$205	Quantity:
10Ω Copper, α = 0.004274
DI-5B35C-01	0°C to +120°C (32°F to +248°F) 10Ω at 0°C	$205	Quantity:
DI-5B35C-02	0°C to 120°C (32°F to +248°F) 10Ω at 25°C	$205	Quantity:
DI-5B35C-03	0°C to 160°C (32°F to 320°F) 10Ω at 0°C	$205	Quantity:
120Ω Nickel, α = 0.00672
DI-5B54N-01	0°C to +300°C (32°F to +572°F)	$205	Quantity:
Accessories
Accessories	Backplanes and Power Supplies.	N/A	Go to Accessories

Note: Pricing outside the U.S. will be higher to account for shipping, taxes, duty, currency fluctuation, local warranty and technical support in your country.
DI-5B Signal Conditioners have typical lead times of 2 weeks ARO.
Order Online! See the Advantages to Placing your orders online.

Knowledge Base and Common Support Issues

The Importance of Isolation

Dimensions and Pinout

Pass-through connections to jump a 5B module socket

How To Calibrate Strain Gage-Based Transducers Using DI-5B38 Strain Amplifiers

Go to the Support Forum

Submit a Support Ticket