MTL5575 MTL  Industries Temperature Converter

The MTL5575 converts a low-level dc signal from a temperature sensor mounted in a hazardous area into a 4/20mA current for driving a safe-area load. Software selectable features include linearisation, ranging, monitoring, testing and tagging for all thermocouple types and 2-, 3-or 4-wire RTDs. (For thermocouple applications the HAZ-CJC plug on terminals 1–3 includes an integral CJC sensor). Configuration is carried out using a personal computer. A single alarm output is provided and may be configured for process alarm or to provide notice of early thermocouple failure.

See also common specification

• Number of channels
      One
• Signal source
      THC types J, K, T, E, R, S, B or N to BS 60584 and XK mV input
      RTDs 2/3/4-wire platinum to BS 60751
      Pt 100, Pt 500, Pt 1000
      Cu-50 & Cu-53
      Ni 100/500/1000 DIN 43760
• Location of signal source
      Zone 0, IIC, T4-6 hazardous area
      Division 1, Group A, hazardous location
• Input signal range
      –75 to +75mV, or 0 to 400Ω (0 to 1000Ω Pt & Ni sensors)
• Input signal span
      3 to 150mV, or 10 to 400Ω (10 to 1000Ω Pt & Ni sensors)
• RTD excitation current
      200µA nominal
• Cold junction compensation
      Automatic or selectable
• Cold junction compensation error
      ≤ 1.0°C
• Common mode rejection
      120dB for 240V at 50Hz or 60Hz (500ms response)
• Series mode rejection
      40dB for 50Hz or 60Hz
• .Calibration accuracy (at 20°C)
   (includes hysteresis, non-linearity and repeatability)
      Inputs: (500ms response)
         mV/THC:     ± 15µV or ± 0.05% of input value(whichever is greater)
         RTD:            ± 80mΩ
         Output:        ± 11µA
• Temperature drift (typical)
      Inputs:
          mV/THC:    ± 0.003% of input value/°C
          RTD:          ± 7mΩ/°C
          Output:       ± 0.6µA/°C
• Example of calibration accuracy and temperature drift
  (RTD input - 500ms response)
       Span:                               250Ω
       Accuracy:                        ± (0.08/250 + 11/16000) x 100%
                                               = 0.1% of span
       Temperature drift:            ± (0.007/250 x 16000 + 0.6) µA/°C
                                               = ±1.0µA/°C
• Safety drive on sensor failure
      Upscale, downscale, or off
• Early burnout
      Early burnout detection for thermocouples (when selected)
      Alarm trips when loop resistance increase is > 50Ω
• Output range
      4 to 20mA nominal into 600Ω max.
• Alarm output (configurable)
      Relay ON in alarm, 250mA @ 35V max
• Maximum lead resistance (THC)
      600Ω
• Response time
      Configurable - 500 ms default(Accuracy at 100/200ms - contact MTL)
• LED indicator
      Green: power and status indication
      Yellow: alarm indication, on when contacts are closed
• Maximum current consumption (with 20mA signal)
      50mA at 24V
• Power dissipation within unit (with 20mA signal)
      1.2W at 24V
• Safety description
      Refer to certificate for parameters. Um=253V rms or dc
• Configurator
      A personal computer running MTL PCS45 software with a
      PCL45USB serial interface