Transmitter, Isolated RTD Input, Loop Power
• Selectable RTD or linear resistance input type or 0-500 ohm input
• 4-20mA output (sink/source)
• 12-32V DC loop/local power
• USB configuration
The TT235 model is a space-saving two-wire transmitter that isolates and converts an RTD sensor input to a proportional 4-20mA signal. Power is received from the output loop current or a DC supply when using a three-wire connection. The transmitter provides sensor excitation plus performs linearization, lead-wire compensation, and lead-break detection.
Setup and calibration are fast and easy with a convenient USB connection to your PC and Acromag’s Windows configuration software.
Advanced signal processing capabilities, variable range input, and convenient USB programming make this instrument a very versatile temperature measurement device. These transmitters can withstand harsh industrial environments and operate reliably across a wide temperature range with very low drift. They feature RFI, EMI, ESD, EFT, and surge protection plus low radiated emissions.
Agility™ Mobile Application Config Tool is available for free. Learn how to enter demo mode, even without a module.
IMPORTANT: To prevent damage or errors from grounded PCs and surges, Acromag strongly recommends use of their USB-ISOLATOR when configuring a TT230 Series transmitter.
USB Connector: USB Mini-B type socket, 5-pin.
USB Data Rate: 12Mbps. USB v1.1 and 2.0 compatible.
USB Transient Protection: Transient voltage suppression on power and data lines.
USB Cable Length: 5.0 meters maximum.
Driver: Not required. Uses built-in Human Interface Device (HID) USB drivers of the Windows operating system.
Default Configuration: 100Ω Pt RTD, α=0.00385, -200 to 850°C input, 4-20mA output, upscale break detect, medium filter.
Input Configuration: Two-, three- or four-wire sensor input connections.
Programs in °C, °K, °F, or ohmic integer values only.
|Input Type||Input Range||Accuracy2|
|RTD, Pt 100Ω||-200 to 850°C
(-328 to 1562°F)
|RTD, Pt 200Ω||-200 to 850°C||±0.3°C, ±0.029%|
|RTD, Pt 500Ω||-200 to 850°C||±0.5°C, ±0.048%|
|RTD, Pt 1000Ω||-200 to 850°C||±1.0°C, ±0.095%|
|RTD, Ni 120Ω
|-80 to 320°C
(-112 to 608°F)
|RTD, Cu 10Ω
|-200 to 270°C
(-328 to 518°F)
|Resistance (linear)1||0 to 450Ω||±0.05Ω, ±0.010%|
Note 1: Linear resistance input range approaches but does not include 0Ω and 500Ω. If exactly 0Ω or 500Ω is measured, break detection is triggered.
Note 2: Rated accuracy (in °C and % of span) applies for input spans greater than 5% of input full-scale.
Input Scaling Adjust: Zero: 0 to 95% of range, typical.
Full scale: 5 to 100% of full scale range, typical.
Lead Break (Sensor Burnout) Detection: Configurable for either upscale or downscale.
Output Range: 4 to 20mA DC.
Under-range capability 3.5mA.
Over-range capability 24mA.
Output Compliance: Rload = (Vsupply - 11V) / 0.020A. Rload = 0 to 650 ohms @ 24V DC.
Output DAC Resolution: 16-bit D/A converter
Output Accuracy: Better than ±0.05% of span, typical (±0.1% max.) for for nominal input spans. Includes the effects of repeatability, terminal point conformity, and linearization, but does not include sensor error.
Ambient Temperature Effect: Better than ±0.008% per °C of input span or ±80ppm/°C, typical. Includes the combined effects of zero and span drift over temperature.
Output Response Time (for step input change)
No filter: 22ms.
Low filter: 50ms.
Medium filter: 160ms.
High filter: 1210ms.
Operating temperature: -40 to 80°C (-40° to 176°F).
Storage temperature: -40 to 85°C (-40 to 185°F).
Relative humidity: 5 to 95% non-condensing.
Power Requirement: 12-32V DC SELV (Safety Extra Low Voltage), 24mA maximum.
Shock and Vibration Immunity: Vibration: 4g, per IEC 60068-2-64. Shock: 25g, per IEC 60068-2-27.
Electromagnetic Compatibility (EMC) Compliance:
Radiated Emissions: BS EN 61000-6-4, CISPR 16.
RFI: BS EN 61000-6-2, IEC 61000-4-3.
Conducted RFI: BS EN 61000-6-2, IEC 61000-4-6.
ESD: BS EN 61000-6-2, IEC 61000-4-2.
EFT: BS EN 61000-6-2, IEC 61000-4-4.
Surge Immunity: BS EN 61000-6-2, IEC 61000-4-5.
CE compliant. Designed for UL/cUL Class I Division 2 Groups ABCD, ATEX / IECEx Zone 2. II 3 G Ex nA IIC T4 Gc -40°C < Ta < +80°C
General: General-purpose enclosure designed for mounting on 35mm “T-type” DIN rail.
Case Material: Self-extinguishing polyamide, UL94 V-0 rated, color light gray. General-purpose NEMA Type 1 enclosure.
I/O Connectors: Removable plug-in terminal blocks rated for 12A/250V; AWG #26-12, stranded or solid copper wire.
Dimensions: 12.5 x 114.5 x 99.0 mm (0.5 x 4.51 x 3.90 inches).
Shipping Weight: 0.22 kg (0.5 pounds) packed.
Features & Benefits
- Easy setup and digital calibration via USB with Windows configuration software
- Selectable RTD or linear resistance input type: Pt RTD (100Ω, 200Ω, 500Ω, or 1000Ω), Ni RTD (120Ω), Cu RTD (10Ω), or Resistance (0-450Ω)
- 1500V isolation between input/output circuits
- Space-saving 12.5mm (0.5 inch) unit with pluggable terminals for convenient wiring
- High accuracy, linearity, stability, and reliability
- Supports normal or reverse-acting output
- Supports sink or source output wiring
- User-selectable filtering (none, low, med., high)
- Fast response (as low as 22ms)
- Selectable upscale or downscale operation for sensor errors and lead-break detection
- NAMUR-compliant output loop current
- Shock (25g) and vibration (4g) resistant
- Wide ambient operation (-40 to 80°C)
- CE compliant. UL/cUL Class I Div 2, ATEX / IECEx Zone 2 approvals