4-20mA Signal Isolators

Acromag offers the industry’s best selection of 4-20mA signal isolators. Multi-channel 2-wire, 3-wire, and 4-wire isolators and isolated transmitters with AC, DC or loop-powered operation. Also offered is a loop-powered isolator with display (panel meter). Optical or galvanic isolation eliminate ground loop errors, reduce noise, and block high voltage transient surges. All Acromag isolators will withstand 1500V AC for 60 seconds and provide continuous 250V AC or 354V DC common-mode protection of your precious equipment. Acromag features solve many tough problems. Our multi-channel modules reduce costs and save space. Browse our selection below.

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    611T, 612T: Single or Dual Channel, DC Voltage/Current Input, DC-Powered Transmitters

    • ±100V DC, 0 to 100mA DC, 0 to 20A AC (with optional sensor) input
    • 0 to 20mA, 0 to 10V DC output
    • 10-36V DC power
    • Universal DC I/O transmitters with auto-configuration and self-ranging capabilities
    These units receive DC current or voltage input signals, provide isolation, and output proportional DC current or voltage signals. With support for universal DC I/O ranges, 610T series transmitters provide a solution for a wide variety of isolation and signal conversion tasks.
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    631T, 632T: Single / Dual Channel Isolator

    • 4 to 20mA DC input
    • 4 to 20mA DC output
    • 12-36V DC SELV, 90-250V AC power
    • Single or dual I/O with a dual output model and full isolation
    These units receive 4-20mA process current inputs and provide isolated 4-20mA output signals. Each channel operates independently and is isolated from the others to prevent interaction between channels. Galvanic isolation eliminates ground loops, reduces noise, and blocks transient signals.
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    651T, 652T: Multi-Channel, Two-Wire Isolators

    • DC current input
    • Single/dual-channel DC-powered isolators
    These units receive 4-20mA process current inputs and provide isolated 4-20mA output signals. Each channel operates independently and is isolated from the others to prevent interaction between channels.
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    671T, 672T, 674T: Multi-Channel, Two-Wire Isolators

    • DC current input
    • Single, dual, or quad I/O loop-powered isolators
    These units receive 4-20mA process current inputs and provide isolated 4-20mA output signals. Power is derived from the input signal current. Each channel operates independently and is isolated from the others to prevent interaction between channels.
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4-20mA Signal Isolators Continued

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Signal Isolators For Signal Conditioning

As your I/O experts, Acromag is here to help! Below are three of our most popular application notes and whitepapers related to our signal isolators. Many times choosing the right isolator requires more than just comparing the number of channels and the cost per point. Find more application notes, white papers and support here: https://www.acromag.com/support/

Top 3 Ethernet Industrial Isolation Papers:

Some signal isolators are ideal for applications that require an isolator with a power supply in series with the output signal. Power is obtained from the output loop. The isolator must control current draw from the power supply in the output loop which is the 4-20mA signal. Since output and power share the same two wires, this type of isolator can be placed anywhere between the field sensing device and the PLC/DCS or monitoring device. Usually, the isolator is located close to the field device. Since both the input and output signal are 4-20mA, location of the device is not critical.

Other signal isolators are useful when adding and isolating a monitoring instrument to an existing current loop. When adding a field device such as a recorder or display, no additional power source is required for the added loop or for the isolator. The isolator's output is powered by the input loop power and drives passive loads only.