CDTX45-Series

Supported Applications

The Omega CDTX-45 is a 2-Wire Isolated Conductivity Transmitter System designed for monitoring and control of conductivity. The system utilizes a four-electrode sensor with titanium electrodes to provide chemical resistance and includes electrode coating rejection diagnostics to compensate for fouling. It displays conductivity on the main display and can show total dissolved solids (TDS), sensor temperature, and output loop current on the secondary display.

Operating Conditions & Performance

The CDTX-45 transmitter operates within an ambient range of -20 to 60°C (-4 to 140°F) with a humidity rating of 0 to 95% RH, non-condensing. The process temperature input is selectable for Pt1000 or Pt100 RTD sensors and covers a range of -10.0 to 110.0°C (14 to 230°F). Performance specifications include an accuracy of 0.3% of span (± 0.1 µS) and repeatability of 0.3% of span (± 0.1 µS), with a sensitivity of 0.05% of span (± 0.1 µS). The instrument response time is 12 sec, and stability is rated at 0.1% of span per 24 hours, non-cumulative.

Measurement ranges are automatic or manual across the following spans: 0.0 to 2.0 µS, 0.0 to 20.0 µS, 0 to 200 µS, 0 to 2000.00 µS, and 0.00 to 2.00 µS. The system also supports ranges of 0.0 to 2000 mS and % Concentration.

Key Performance Metrics

• Accuracy: 0.3% of span (± 0.1 µS)
• Sensitivity: 0.05% of span (± 0.1 µS)
• Stability: 0.1% of span per 24 hours, non-cumulative
• Warm-up Time: 7 sec
• Temperature Drift: Span or zero, 0.03% of span/°C
• Max Cable Length: 18.3 m (60')

Configuration Options

The series offers configurable power and output options to suit different installation requirements. The standard CDTX-45 is a loop-powered transmitter for 2-wire DC applications operating on 16 to 35 Vdc, providing galvanic isolation of 600V. An alternative configuration, the CDTX-45-115VAC-R2, supports 115/230 Vac power and includes two SPDT relay outputs rated at 6 Amp @ 250 Vac or 5 Amp @ 24 Vdc.

Outputs and Signals

• Analog Output: Loop powered 4 to 20 mA output for conductivity (CDTX-45); Dual 4 to 20 mA outputs with the second programmable for temperature or conductivity (CDTX-45-115VAC-R2).
• Relay Output: Two SPDT, 6 Amp @ 250 Vac, 5 Amp @ 24 Vdc (available on CDTX-45-115VAC-R2 only).

Housing and Mounting

The transmitter features a NEMA 4X enclosure constructed from polycarbonate with stainless steel hardware, described as weatherproof and corrosion resistant. It includes three PG-9 openings with gland seals for electrical connections. The unit measures 112 H x 112 W x 89 mm D (4.4 x 4.4 x 3.5") and weighs 0.45 kg (1 lb). Mounting options include wall, panel, or pipe/header configurations.

Sensor Construction

The CDE-45P sensor features a PEEK™ body construction with titanium electrodes for chemical resistance. The system includes electrode diagnostics to detect coating rejection and compensate for fouling conditions.

Key Product Differences

The series is available in distinct configurations based on power supply and output requirements:

• CDTX-45: Conductivity meter/transmitter, loop-powered 16 to 35 Vdc (2-wire device), single 4 to 20 mA conductivity output. Electrode sold separately.
• CDTX-45-115VAC-R2: Conductivity meter/transmitter with 115/230 Vac power, dual 4 to 20 mA outputs (second programmable for temperature or conductivity), and two SPDT relay outputs. Electrode sold separately.
• CDE-45P: The four-electrode conductivity sensor compatible with the transmitter system.

Additional accessories include the PSU-93 unregulated power supply (16 to 23 Vdc) and PHTX-45-SMH submersion mounting hardware (1.8 m / 6'). The meter and electrode are sold separately, with ordering examples typically pairing CDTX-45 or CDTX-45-115VAC-R2 transmitters with the CDE-45P sensor.