Choosing an Isolator - by application

The following guide is for users who require guidance on their choice of isolator for a new installation. For a given application the choice is between DIN-rail mounting (MTL5000/MTL5500 Series) and backplane mounting (MTL4000/MTL4500 Series) devices.

If additional guidance is required, contact your local MTL representative.
 
Analogue Inputs (high level)
  • 2-wire transmitters, 4-20mA conventional and 'smart'
  • vibration transducer
  • loop isolator
    		•
    Analogue Inputs (low level)
  • thermocouples and mV sources
  • 2, 3 and 4-wire RTDs
  • strain-gauge bridges
    		•
    Analogue Outputs
  • controller outputs (I/P converters)
    		•
    Digital (ON/OFF) Inputs
  • switches/proximity detectors
    		•
    Digital (ON/OFF) Outputs
  • switches, proximity detectors, SIL3
  • alarms, LEDs, solenoid valves, etc.
  • switch output to hazardous area
    		•
    Pulse Input
  • turbine/flowmeters
    • Miscellaneous
  • fire/smoke detectors
  • signal transfer
  • trip amplifiers
  • earth leakage detector
    		•
    Analogue Input - 2-wire transmitters, 4-20mA conventional and 'smart'
    Device
    No. of
    channels
    Output to
    hazardous area
    		 Important features
    DIN-rail mounting devices
    MTL5041

    1
    16.5V min.
    @ 20mA
    		0 to 1kohm safe-area load
    MTL5042 1 16.5V min
    @ 20mA    		 Compatible with most smart transmitters, high accuracy
    MTL5043 1 16.5V min
    @ 20mA    		 0 to 550 ohm safe-area load
    MTL5044
    2
    16.5V min
    @ 20mA
    		 0 to 550 ohm safe-area load
    MTL5541 1 16.5V min
    @ 20mA    		 Compatible with most smart transmitters
    MTL5544 2 16.5V min
    @ 20mA    		 Compatible with most smart transmitters. Also 1-in-2-out configuration
    Backplane mounting devices
    MTL4041A 1 Passive
    4/20mA input    		 Use with 3/4-wire smart transmitters
    MTL4041B 1 15V min
    @ 20mA    		 Compatible with most smart transmitters
    MTL4041P 1 16.3V min
    @ 20mA    		 As MTL4041B but with a higher power output
    MTL4042 1 18V min
    @ 20mA    		 IIB gas groups, 2-wire transmitters
    MTL4043 1 15V min
    @ 20mA    		 Suitable for conventional and HART transmitters, current-sink ouput
    MTL4044 2 15V min
    @ 20mA    		 Suitable for conventional and smart transmitters
    MTL4048 1 Loop powered Suitable for 'intelligent' Foxboro transmitters
    MTL4541 1 16.5V min
    @ 20mA    		 Compatible with most smart transmitters
    MTL4541B 1 16.5V min
    @ 20mA    		 As MTL4541 but adapted for substitution on legacy backplanes
    MTL4541P 1 17.6V min
    @ 20mA    		 As MTL4541B but with a higher power output
    MTL4544 2 16.5V min
    @ 20mA    		 Compatible with most smart transmitters. Also 1-in-2-out configuration
    MTL4544B 2 16.5V min
    @ 20mA    		 As MTL4544 but adapted for substitution on legacy backplanes
    Analogue Input - vibration transducer
    Device No. of
    channels    		 Signal monitored Main features
    DIN-rail mounting devices
    MTL5031 1 Vibration
    transducer     		Compatible with vibration and accelerometer transducers
    Backplane mounting devices
    MTL4031 1 Vibration
    transducer    		 Compatible with vibration and accelerometer transducers
    Analogue - loop isolator
    Device No. of
    channels    		 Output to
    hazardous area    		 Main features
    DIN-rail mounting devices
    MTL5040 1 x AI +
    1 x AO    		 16.5V @ 20mA
    Vmax 11V @ 20mA    		 Analogue input and output module
    Analogue Input - thermocouple and mV sources
    Device No. of
    channels    		 Output to
    safe area    		 Main features
    DIN-rail mounting devices
    MTL5074 1 4/20mA Configurable, built-in CJC
    MTL5081 1 0 to ±50mV Selectable upscale or downscale
    MTL5575 1 4/20mA Configurable, built-in CJC, early burnout detection facility
    Backplane mounting devices
    MTL4073 1 4/20mA Configurable, built-in CJC
    MTL4081 1 0 to ±50mV Selectable upscale or downscale
    MTL4575 1 4/20mA Configurable, built-in CJC, early burnout detection facility
    Analogue Input - 2, 3 and 4-wire RTDs
    Device No. of
    channels    		 Output to
    safe area    		 Main features
    DIN-rail mounting devices
    MTL5074 1 4/20mA Configurable
    MTL5082 1 10 to 400 ohm Independent selection of 2, 3 or 4-wire RTDs on safe and hazardous area sides
    MTL5575 1 4/20mA Configurable, built-in CJC, early burnout detection facility
    Backplane mounting devices
    MTL4073 1 4/20mA Configurable
    MTL4575 1 4/20mA Configurable, many sensor types and ranges
    Analogue Input - strain-gauge bridges
    Device No. of
    channels    		 Output to
    safe area    		 Main features
    Backplane mounting devices
    MTL4081 1 0 to ±50mV For monitoring bridge voltage
    MTL4083 1 0 to +12V Can be used with MTL4081 for monitoring bridge supply
    Analogue Output - controller outputs, I/P converters
    Device
    No. of
    channels
    Output to
    hazardous area
    		 Important features
    DIN-rail mounting devices
    MTL5045

    1
    0mA <Io<20mA
    Vmax = 16V
    		 Separately powered
    MTL5046 1 0mA <Io<24mA
    Vmax = 16V    		 Smart communications, LFD, high accuracy
    MTL5049 2 0mA <Io<24mA
    Vmax = 11V    		 Separately powered
    MTL5546 1 1mA <Io<24mA
    Vmax = 16V    		 Suitable for HART valve positioners, LFD
    MTL5549 2 1mA <Io<24mA
    Vmax = 16V    		 Suitable for HART valve positioners, LFD
    Backplane mounting devices
    MTL4045B 1 1mA <Io<21.4mA
    Vmax = 16V    		 Open or short circuit detection, separately powered
    MTL4045C 1 1mA <Io<21.4mA
    Vmax = 16V    		 Open circuit detection, separately powered
    MTL4046/
    MTL4046C    		 1 1mA <Io<26mA
    Vmax = 16V    		 Suitable for HART valve positioners, LFD
    MTL4046P 1 1mA <Io<26mA
    Vmax = 17.4V    		 Separately powered, LFD
    MTL4546/
    MTL4546C    		 1 1mA <Io<24mA
    Vmax = 16V    		 Suitable for HART valve positioners, LFD
    MTL4549/
    MTL4549C    		 2 1mA <Io<24mA
    Vmax = 16V    		 Suitable for HART valve positioners, LFD
    Digital Input - switches / proximity detectors
    Device
    No. of
    channels
    Output to
    safe area
    		 Important features
    DIN-rail mounting devices
    MTL5011B 1 1 x SPDT Phase reversal LFD
    MTL5012 1 1 x solid-state Independent phase reversal, LFD
    MTL5014 1 2 x SPDT Phase reversal, selectable slave/LFD
    MTL5015 2 2 x solid-state Selectable independent phase reversaL/LFD
    MTL5017 2 2 x SPST Independent phase reversal, LFD
    MTL5018 2
    2 x SPDT
    		 Selectable independent phase reversaL/LFD
    MTL5510 4 4 x solid state Can switch +ve or –ve polarity signals
    MTL5510B 4 4 x solid state Mult-function selectable
    MTL5511 1 1 x SPDT Switch/proximity detector repeater
    MTL5513 2 2 x solid state dc to 1kHz frequency response
    MTL5514 1 1 x SPDT
    1 x SPDT     		Switch/proximity detector repeater
    Independent LFD output
    MTL5516C 2 2 x SPDT Switch/proximity detector repeater
    MTL5517 2 2 x SPDT
    1 x SPDT    		 Switch/proximity detector repeater
    Independent LFD output
    Backplane mounting devices
    MTL4013 2 2 x solid-state dc to 5kHz frequency response
    MTL4014 1 1 x SPST
    1 x SPDT     		Switch/proximity detector repeater
    Independent LFD output
    MTL4015 1 2 x DPST Phase reversal LFD
    MTL4016 2 2 x DPST Phase reversal LFD
    MTL4017 2 2 x SPST
    1 x SPST    		 Switch/proximity detector repeater
    Independent LFD output
    MTL4510 4 4 x solid state Can switch +ve or –ve polarity signals
    MTL4510B 4 4 x solid state Mult-function selectable
    MTL4511 1 1 x SPDT Switch/proximity detector repeater
    MTL4513 2 2 x solid state dc to 1kHz frequency response
    MTL4514 1 1 x SPDT
    1 x SPDT     		Switch/proximity detector repeater
    Independent LFD output
    MTL4516 2 2 x SPDT Switch/proximity detector repeater
    MTL4516C 2 2 x SPDT Switch/proximity detector repeater
    MTL4517 2 2 x SPDT
    1 x SPDT     		Switch/proximity detector repeater
    Independent LFD output
    Digital Input - switch/proximity detectors, SIL3
    Device No. of
    channels    		 Signals monitored Important features
    DIN-rail mounting devices
    MTL5113P 1 24V logic Safety related, SIL3
    Backplane mounting devices
    MTL4113P 1 24V logic Safety related, SIL3
    Digital Output - alarms, LEDs, solenoid valves, etc
    Device
    No. of
    channels
    Output to
    hazardous area
    		 Important features
    DIN-rail mounting devices
    MTL5021 1 12.85V<Vo<21.4V
    Imax = 45mA    		 IIC gas groups, loop powered
    MTL5022 1 12.9V<Vo<21.4V
    Imax = 60mA    		 IIB gas groups, loop powered
    MTL5023 1 12.85V<Vo<21.4V
    Imax = 45mA    		 IIC gas groups, separately powered, independent LFD output
    MTL5024 1 12.85V<Vo<21.4V
    Imax = 45mA    		 IIC gas groups, separately powered, phase reversal
    MTL5025 1 8.6V<Vo<21.4V
    Imax = 45mA    		 IIC gas groups, low-current output, loop powered,
    MTL5521 1 12.8V<Vo<24V
    Imax = 48mA    		 IIC gas groups, loop powered
    MTL5522 1 9.9V<Vo<21.4V
    Imax = 70mA    		 IIB gas groups, loop powered
    MTL5523 1 12.8V<Vo<24V
    Imax = 48mA    		 Independent LFD output
    MTL5524 1 12.8V<Vo<24V
    Imax = 48mA    		 Safety override feature, separately powered
    MTL5525 1 7V<Vo<24V
    Imax = 48mA    		 Safety override, low power output
    Backplane mounting devices
    MTL4021 1 10V<Vo<25.5V
    Imax = 50mA    		 Safety override feature, IIC gases, separately powered
    MTL4021S 1 10V<Vo<25.5V
    Imax = 50mA    		 Fail-safe override from 24V logic signal
    MTL4023 1 14V<Vo<25V
    Imax = 45mA    		 Independent LFD output
    MTL4024 1 10V<Vo<25.5V
    Imax = 50mA    		 Loop powered; fail-safe override from 24V logic signal
    MTL4025 1 8V<Vo<25V
    Imax = 50mA    		 Safety override, low current output
    MTL4421RS 1 Relay For safe area only
    MTL4521 1 12.8V<Vo<24V
    Imax = 48mA    		 Loop powered
    MTL4523
    MTL4523R     		1 12.8V<Vo<24V
    Imax = 48mA    		 Independent LFD output
    MTL4523L 1 12.8V<Vo<24V
    Imax = 48mA    		 Loop powered, independent LFD output
    MTL4524 &
    MTL4524S    		 1 12.8V<Vo<24V
    Imax = 48mA    		 Safety override feature, separately powered
    MTL4525 1 7V<Vo<24V
    Imax = 48mA    		 Safety override, low power output
    Digital Output - switch output to hazardous area
    Device No. of
    channels    		 Signals monitored Important features
    Backplane mounting devices
    MTL4215 1 1 x DPDT Safe-area switch input
    MTL4216 2 2 x SPDT Dual safe-area switch inputs
    Pulse Input - turbine / flowmeters
    Device
    No. of
    channels
    Input from
    hazardous area
    		 Important features
    DIN-rail mounting devices
    MTL5032
    1
    Switch, proximity detector, current pulse, voltage pulse
    		 Voltage and current inputs from 2 or 3-wire transmitters
    MTL5042 1 2-wire pulse e.g. 2-wire turbine and vortex flowmeters
    MTL5541 1 2-wire pulse e.g. 2-wire turbine and vortex flowmeters
    Backplane mounting devices
    MTL4013 2 1mA <Io<21.4mA
    Vmax = 16V    		 e.g. 2-wire positive displacement flowmeters
    MTL4032 1 1mA <Io<21.4mA
    Vmax = 16V    		 Voltage and current inputs from 2 or 3-wire transmitters
    MTL4041B 1 1mA <Io<26mA
    Vmax = 16V    		 e.g. 2-wire turbine and vortex flowmeters
    MTL4513 2 Switch, proximity detector e.g. 2-wire positive displacement flowmeters
    MTL4541 1 2-wire pulse e.g. 2-wire turbine and vortex flowmeters
    Fire / Smoke detectors
    Device No. of
    channels    		 Output to
    hazardous area    		 Important features
    DIN-rail mounting devices
    MTL5061 2 Loop powered 0–40mA, fire and smoke detectors
    Backplane mounting devices
    MTL4061 2 Loop powered 0–40mA, fire and smoke detector
    Signal transfer - safe area to safe area - via hazardous area
    Device
    pair     		No. of
    channels    		 Signal transferred Important features
    DIN-rail mounting devices
    MTL5042 &
    MTL5045     		1 4/20mA Receiver
    Driver
    MTL5541 &
    MTL5546    		 1 4/20mA Receiver
    Driver
    MTL5051 &
    MTL5051     		1 RS232 or RS422 Either can be used as receiver or driver
    Backplane mounting devices
    MTL4041B &
    MTL4045C    		 1 4/20mA Receiver

    Driver
    MTL4041A &
    MTL4046C    		 1 4/20mA smart Receiver

    Driver
    MTL4541 &
    MTL4546    		 1 4/20mA Receiver
    Driver
    Trip amplifiers
    Device No. of
    channels    		 Signals monitored Important features
    DIN-rail mounting devices
    MTL5314 1 4/20mA Configurable, one or two alarms
    Backplane mounting devices
    MTL4403 1 4/20mA Two alarms
    Earth-leakage detector
    Device No. of
    channels    		 Output to
    safe area    		 Important features
    Backplane mounting devices
    MTL4220 8 1 x SPST Can monitor up to 8 loops