SCM7B47 Isolated Linearized Thermocouple Input Modules FEATURES DESCRIPTION INTERFACES TO TYPES J, K, T, E, R, S, B AND N THERMOCOUPLES SCM7B47 modules accept a single channel of input from Type J, K, T, E, R, S, B, or N thermocouples. The signal is filtered, isolated, amplified, linearized, and converted to a high level analog voltage for output to the process control system (Figure 1). LINEARIZES THERMOCOUPLE SIGNALS PROVIDES HIGH LEVEL VOLTAGE OUTPUTS Linearization is achieved by creating a non-linear transfer function through the module itself; refer to AN505. This non-linear transfer function is configured at the factory and is designed to be equal and opposite to the thermocouple non-linearity. 1500Vrms TRANSFORMER ISOLATION ACCURACY, 0.06% TO 0.16% OF SPAN TYPICAL ANSI/IEEE C37.90.1-1989 TRANSIENT PROTECTION Cold junction compensation (CJC) is performed using an NTC thermistor (see "Additional SCM7B Part Numbers" section for P/N and AN701 for further information) externally mounted under the field-side terminal block on the backpanel (Figure 1). Open thermocouple detection is upscale using a 30nA current source in the input circuitry. INPUT PROTECTED TO 120Vrms CONTINUOUS NOISE, 1mV PEAK (5MHz), 500V RMS (100KHz) CMRR, 160dB These modules incorporate a five-pole filtering approach to maximize both time and frequency response by taking advantage of both Thomson (Bessel) and Butterworth characteristics. One pole of the filter is on the field side of the isolation barrier; four are on the process control system side. NMR, UP TO 85dB EASY DIN RAIL MOUNTING CSA CERTIFIED, FM APPROVAL PENDING After the initial field-side filtering, the input signal is chopped by a proprietary chopper circuit and transferred across the transformer isolation barrier, suppressing transmission of common mode spikes and surges. The signal is then reconstructed and filtered for process control system output. CE COMPLIANT Modules accept a wide 14 - 35VDC power supply range (+24VDC nominal). Their compact packages (2.13"x1.705"x0.605" max) save space and are ideal for high channel density applications. They are designed for easy DIN rail mounting using any of the "-DIN" backpanels. 1500V Isolation Barrier Refer to AN701 for Vout to temperature conversion information Shield** + - X Surge Suppression, Protection, 2 LPF (1 pole), Open Detection and CJC 0 1 Thermocouple RT* Iso-Chopper IITM Amplifier Pat Pending LPF (4 pole) and Linearization 4 5 VOUT COM Backpanel Term Block Field-Side *RT is a backpanel mounted NTC thermistor used as a cold junction compensation (CJC) sense element. +V -V 3 dc Supply **Shield ground-tie shown for ungrounded thermocouple configuration. Fig 1: SCM7B47 Block Diagram DATAFORTH A Burr-Brown Company (R) Process Control System-Side Call 800-444-7644 For Information and Assistance 126 dc Supply/ Oscillator VS (14-35V dc) SPECIFICATIONS Typical at 25C and +24VDC Module SCM7B47 Input Signal Range Thermocouple1 (See Ordering Information below) -30nA Current Resistance Normal Power Off Overload Protection Continous Transient 50M 30k min 30k min 120Vrms max ANSI/IEEE C37.90.1-1989 Output Signal Range2 Effective Available Power2 Resistance Protection Voltage/Current Limit 40mW <1 Continuous Short-to-Ground 12V, 14mA **THERMOCOUPLE ALLOY COMBINATIONS Standards: DIN IEC 584, ANSI MC96-1-82, JIS C 1602-1981 1500Vrms ANSI/IEEE C37.90.1-1989 160dB 3 TYPE (See Ordering Information below) Accuracy Stability (-40C to +85C) Gain Input Offset Zero Suppression Output Offset Noise Peak @ 5MHz B/W RMS @ 10Hz to 100kHz B/W Peak @ 0.1Hz to 10Hz B/W CJC Accuracy5, +5C to +45C ambient Open Input Response Open Input Detection Time 40ppm/C 0.5V/C 0.005%(Vz)4/C 0.002% Span/C 1mV 500V 1V 0.25C Typ, 1C max Upscale 10s max Frequency and Time Response Bandwidth, -3dB NMR (50/60Hz) Step Response, 90% Span Environmental Operating Temperature Range Storage Temperature Range Relative Humidity Emmissions Immunity OUTPUT RANGES AVAILABLE PART NUMBER MODIFIER EXAMPLE (none) A D SCM7B47J-01 SCM7B47J-01A SCM7B47J-01D +1 to +5V 0 to +5V 0 to +10V 14 to 35VDC 16mA 0.0001%/%VS Mechanical Dimensions (H)(W)(D) Iron vs. Copper-Nickel Nickel-Chromium vs. Nickel-Aluminum Copper vs. Copper-Nickel Nickel-Chromium vs. Copper-Nickel Platinum-13% Rhodium vs. Platinum Platinum-10% Rhodium vs. Platinum Platinum-30% Rhodium vs. Platinum-6% Rhodium Nickel-14.2% Chromium-1.4% Silicon vs. Nickel-4.4% Silicon- 0.1% Magnesium OUTPUT RANGE 3Hz 80/85dB 150ms Supply Voltage Current2 Sensitivity MATERIAL J K T E R S B N 2.13" x 1.705" x 0.605" max 54.1mm x 43.3mm x 15.4mm max -40C to +85C -40C to +85C 0 to 90% noncondensing EN50081-1, ISM Group 1, Class A (Radiated, Conducted) EN50082-1, ISM Group 1, Class A (ESD, RF, EFT) SCM7B CMV (Input-to-Output) Continuous Transient CMRR (50 or 60Hz) NOTES 1 Thermocouple characteristics per NIST monograph 175, ITS-90. 2 Output Range and Supply Current specifications are based on minimum output load resistance. Minimum output load resistance is calculated by VOUT2/PE, where PE is the output Effective Available Power that guarantees output range, accuracy, and linearity specifications. 3 Accuracy includes the effects of repeatability, hysteresis, and conformity. 4 VZ is the nominal input voltage that results in a 0V output. 5 The CJC sensor accuracy should be added to the module accuracy and thermocouple accuracy to compute overall measurement accuracy. ORDERING INFORMATION MODEL ** SCM7B47J-01 SCM7B47J-02 SCM7B47K-03 SCM7B47K-04 SCM7B47T-05 SCM7B47T-06 SCM7B47E-07 SCM7B47R-08 SCM7B47S-09 SCM7B47B-10 SCM7B47N-11 INPUT RANGE ACCURACY (TYPICAL)3, 5 0C to +760C (+32F to +1400F) -100C to +300C (-148F to +572F) 0C to +1300C (+32F to +2372F) 0C to +600C (+32F to +1112F) 0C to +400C (+32F to +752F) -100C to +200C (-148F to +392F) 0C to +900C (+32F to +1652F) +500C to +1750C (+932F to +3182F) +700C to +1750C (+1292F to +3182F) +800C to +1800C (+1472F to +3272F) +200C to +1300C (+392F to +2372F) 0.11% Span (0.84C) 0.10% Span (0.40C) 0.11% Span (1.43C) 0.06% Span (0.36C) 0.13% Span (0.52C) 0.16% Span (0.48C) 0.11% Span (0.99C) 0.10% Span (1.25C) 0.08% Span (0.84C) 0.12% Span (1.20C) 0.09% Span (0.99C) 127 ACCURACY (MAXIMUM)3, 5 0.32% Span (3.43C) 0.30% Span (1.20C) 0.32% Span (4.16C) 0.18% Span (1.08C) 0.38% Span (1.52C) 0.47% Span (1.41C) 0.34% Span (3.06C) 0.30% Span (3.75C) 0.25% Span (2.63C) 0.35% Span (3.50C) 0.27% Span (2.97C) Call 800-444-7644 For Information and Assistance DATAFORTH A Burr-Brown Company (R)