SCM7B37 Isolated Thermocouple Input Modules FEATURES DESCRIPTION INTERFACES TO TYPE J, K, T, E, R, S, AND B THERMOCOUPLES SCM7B37 modules accept a single channel of input from Type J, K, T, E, R, S, or B thermocouples. The signal is filtered, isolated, amplified, and converted to a high level analog voltage for output to the process control system (Figure 1). PROVIDES HIGH LEVEL VOLTAGE OUTPUTS 1500Vrms TRANSFORMER ISOLATION 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. ACCURACY, 0.03% OF SPAN TYPICAL, 0.1% MAX ANSI/IEEE C37.90.1-1989 TRANSIENT PROTECTION INPUT PROTECTED TO 120Vrms CONTINUOUS NOISE, 500V PEAK (5MHz), 250V RMS (100KHz) 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. CMRR, 160dB NMR, UP TO 85dB EASY DIN RAIL MOUNTING 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. CSA CERTIFIED, FM APPROVAL PENDING 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. Refer to AN701 for Vout to temperature conversion information 1500V Isolation Barrier 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) 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: SCM7B37 Block Diagram DATAFORTH A Burr-Brown Company (R) Process Control System-Side Call 800-444-7644 For Information and Assistance 120 dc Supply/ Oscillator VS (14-35V dc) SPECIFICATIONS Typical at 25C and +24VDC Module SCM7B37 Input Signal Range Thermocouple1 (See Ordering Information below) -30nA Bias Current Resistance Normal Power Off Overload Protection Continous Transient 50M 30k min 30k min 120Vrms max ANSI/IEEE C37.90.1-1989 40mW <1 Continuous Short-to-Ground 12V, 14mA CMV (Input-to-Output) Continuous Transient CMRR (50 or 60Hz) **THERMOCOUPLE ALLOY COMBINATIONS Standards: DIN IEC 584, ANSI MC96-1-82, JIS C 1602-1981 TYPE 1500Vrms ANSI/IEEE C37.90.1-1989 160dB 0.03% Span typical, 0.1% Span max See Ordering Information Accuracy3 Nonlinearity4 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 Accuracy6, +5C to +45C ambient Open Input Response Open Input Detection Time 35ppm/C 0.5V/C 0.005%(Vz)5/C 0.002% Span/C 3Hz 80/85dB 150ms Supply Voltage Current2 Sensitivity 14 to 35VDC 12mA 0.0001%/%VS Mechanical Dimensions (H)(W)(D) Environmental Operating Temperature Range Storage Temperature Range Relative Humidity Emmissions Immunity 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 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 linearity. 4 Nonlinearity is calculated using the best-fit straight line method. 5 VZ is the nominal input voltage that results in a 0V output. 6 The CJC sensor accuracy should be added to the module accuracy and thermocouple accuracy to compute the overall measurement accuracy. 500V 250V 1V 0.25C typ, 1C max Upscale 10s max Frequency and Time Response Bandwidth, -3dB NMR (50/60Hz) Step Response, 90% Span MATERIAL J K T E R S B N SCM7B Output Signal Range2 Effective Available Power2 Resistance Protection Voltage/Current Limit 2.13" x 1.705" x 0.605" max 54.1mm x 43.3mm x 15.4mm max OUTPUT RANGES AVAILABLE OUTPUT RANGE PART NUMBER MODIFIER EXAMPLE -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) +1 to +5V 0 to +5V 0 to +10V (none) A D SCM7B37J-01 SCM7B37J-01A SCM7B37J-01D ORDERING INFORMATION MODEL ** SCM7B37J-01 SCM7B37J-10 SCM7B37J-11 SCM7B37J-12 SCM7B37J-13 SCM7B37K-02 SCM7B37K-20 SCM7B37K-21 SCM7B37K-22 SCM7B37K-23 SCM7B37T-03 SCM7B37E-04 SCM7B37R-05 SCM7B37S-06 SCM7B37B-07 INPUT RANGE -100C to +760C (-148F to +1400F) 0C to +200C (+32F to +392F) 0C to +400C (+32F to +752F) 0C to +600C (+32F to +1112F) +300C to +600C (+572F to +1112F) -100C to +1350C (-148F to +2462F) 0C to +300C (+32F to +572F) 0C to +600C (+32F to +1112F) 0C to +1200C (+32F to +2192F) +600C to +1200C (+1112F to +2192F) -100C to +400C (-148F to +752F) 0C to +900C (+32F to +1652F) 0C to +1750C (+32F to +3182F) 0C to +1750C (+32F to +3182F) 0C to +1800C (+32F to +3272F) ACCURACY (TYP)3 ACCURACY (MAX)3 NONLINEARITY (TYP)4 NONLINEARITY (MAX)4 0.03% " " " " " " " " " " " " " " (0.26C) (0.06C) (0.12C) (0.18C) (0.09C) (0.44C) (0.09C) (0.18C) (0.36C) (0.18C) (0.15C) (0.27C) (0.53C) (0.53C) (0.54C) 0.1% " " " " " " " " " " " " " " (0.86C) (0.20C) (0.40C) (0.60C) (0.30C) (1.45C) (0.30C) (0.60C) (1.20C) (0.60C) (0.50C) (0.90C) (1.75C) (1.75C) (1.80C) 121 0.1% " " " " " " " " " " " " " " (0.09C) (0.02C) (0.04C) (0.06C) (0.03C) (0.15C) (0.03C) (0.06C) (0.12C) (0.06C) (0.05C) (0.09C) (0.18C) (0.18C) (0.18C) 0.02% " " " " " " " " " " " " " " (0.17C) (0.04C) (0.08C) (0.12C) (0.24C) (0.29C) (0.06C) (0.12C) (0.24C) (0.12C) (0.10C) (0.18C) (0.35C) (0.35C) (0.36C) Call 800-444-7644 For Information and Assistance DATAFORTH A Burr-Brown Company (R)