SPRTX-STCTX-Srs-Sig-Cond

Supported Applications

The Omega SPRTX and STCTX series are universal temperature connector transmitters designed for industrial signal conditioning of RTD and thermocouple sensors. The SPRTX models convert the resistive change of a 100 Ω, 0.00385 3-wire PT100 sensor into an amplified analog output, while STCTX models amplify the non-linear millivolt output from Type J, K, or T thermocouples. These devices feature an encapsulated micro-miniature signal conditioner built directly into the connector housing to replace other style transmitters.

Key functional capabilities include:

• Sensor Interface: Models support 100 Ω RTDs (SPRTX) and Type J, K, or T thermocouples (STCTX).
• Fault Detection: Provides 'Open Sensor Wire' signal indication for diagnostics.
• Lead Compensation: The SPRTX model compensates for long lead wires in RTD applications.

Note: The SPRTX and STCTX Series are not for use in medical or nuclear applications, nor in flammable or explosive environments.

Operating Conditions & Performance

The series operates within an ambient temperature range of -40 to 85°C (-40 to 185°F). Accuracy specifications vary by sensor type and model:

• SPRTX (RTD): ±0.5% of FS @ 23°C (73°F) ambient.
• STCTX (Thermocouple): ±0.5% of full scale millivolt input @ 23°C (73°F) plus the non-linearity of the thermocouple type; note that STCTX does not compensate for thermocouple non-linearity.
• Ambient Temp Effect: ±0.015 mA/°C.

The response time is 120 ms (0 to 63% FS) with a repeatability of ±0.25°C (±0.5°F). The devices are loop-powered, requiring a supply voltage of 9 to 24 Vdc @ 30 mA max. Maximum loop load resistance is calculated as V = (Vsupply - 9V)/0.020 A.

Measurement Ranges

The series supports the following dedicated temperature ranges by model:

• SPRTX-M1, SPRTX-S1: -99 to 208°C (-146 to 406°F).
• SPRTX-M2, SPRTX-S2: 2 to 569°C (36 to 1056°F).
• STCTX-J1, -K1, -T1: -18 to 121°C (0 to 250°F).
• STCTX-J2, -K2: -18 to 538°C (0 to 1000°F).
• STCTX-K3: -18 to 1093°C (0 to 2000°F).
• STCTX-T2: -18 to 399°C (0 to 750°F).

Configuration Options

The series is configured via specific connector types and range codes. Each unit comes fully assembled with the built-in transmitter, connector, and a 2-wire shielded cable [3 m (10') included]. The output signal is an industry-standard 4 to 20 mA (2-wire).

Input Connections

• SPRTX-M Series: Uses a 3-prong miniature connector (MTP-U-F) for RTD inputs.
• SPRTX-S Series: Uses a 3-prong standard-size connector (OTP-U-F) for RTD inputs.
• STCTX Series: Features the Omega Smart Connector™, a universal thermocouple connector (UST Series).

Housing and Physical Specifications

The electronics are housed in an encapsulated housing. Dimensions vary by model family:

• SPRTX-M1, SPRTX-M2: 24 H x 18 W x 79 mm L (0.96 x 0.70 x 3.12").
• SPRTX-S1, SPRTX-S2: 36 H x 18 W x 83 mm L (1.43 x 0.70 x 3.25").

The maximum weight is 110 g (0.25 lb) with cable.

Available Options and Accessories

• Cabling: TX2-100, a 2-conductor shielded cable, 30 m (100').
• Power Supplies: PSR-24S (screw terminal), PSR-24L (stripped leads, UL), and PSR-24L-230 (230 Vac input, CE).
• Calibration: CAL-3 for NIST-traceable calibration with data; CAL-3-SYSTEM includes the probe.

Key Product Differences

The series is divided into two primary families based on sensor technology and connector style. The SPRTX family serves RTD applications, while the STCTX family serves thermocouple applications.

• SPRTX Models: Designed for 3-wire PT100 (α = 0.00385) inputs. Variants are distinguished by connector size ('M' for miniature, 'S' for standard-size) and range code (*1 or *2). Open sensor wire indication varies by leg: Leg 1 open equals 27 mA; Legs 2 and 3 open equal 2.2 mA.
• STCTX Models: Designed for ungrounded Type J, K, or T thermocouple signals. Variants are distinguished by the specific thermocouple type (J, K, T) and range code (1, 2, or 3). Open sensor indication is signaled as 22 to 27 mA.

Approvals differ between families: SPRTX models are CE marked. STCTX approval status is not explicitly listed in the series data sheet beyond general product context.