Transmitter, RTD Input, Loop Power
• 100 ohm Pt RTD or 0-900 ohm input
• 4-20mA output (sink/source)
• 12-32V DC loop/local power
• USB configuration
The TT231 model is a space-saving two-wire transmitter that converts a 100 ohm Platinum 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.more >
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.
IMPORTANT: To prevent damage or errors from grounded PCs and surges, Acromag strongly recommends the 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 Ω/Ω/°C, 0-200°C input, 4-20mA output, upscale break detection.
Input Configuration: Two-, three- or four-wire sensor input connections.
Input Ranges: 100 ohm Platinum RTD, alpha = 375-393, 385 (default), -50 to 850°C (-58 to 1562°F). 0 to 900 ohms linear resistance.
Programs in °C, °F, or ohmic integer values only.
RTD 3/4 wire: -50, -17.78, or 0°C (-58, 0, 32°F).
RTD 2 wire: 0°C (32°F) fixed.
RES: 0 or 100 ohms.
RTD: up to 850°C (1562°F), 50°C (58°F) span minimum.
Resistance: up to 900 ohms, 8 ohm span minimum.
Excitation Current: 0.5mA, nominal, each ± lead.
Lead-Wire Compensation: 25 ohms per lead.
Lead Break (Sensor Burnout) Detection: Configurable for either upscale or downscale.
Input Filter Bandwidth: -3dB at 700Hz, typical, normal mode filter.
Output Range: 4 to 20mA DC.
Under-scale limit adjustable for 2.1 to 3.6mA, nominal.
Over-scale limit adjustable for 21 to 30mA, nominal.
Output Fault Limits (Sensor Fault):
0.4mA below selected under-scale threshold and 1.0mA above over-scale threshold, typical.
Rload = (Vsupply - 8.6V) / 0.020A.
Rload = 0 to 750 ohms @ 24V DC.
Better than ±0.1% of span, typical for spans less than 500°C. 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): 500μS, typical with 250 ohm load (to reach 98% of final output value).
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: 9-32V DC SELV (Safety Extra Low Voltage), 30mA max.
Shock and Vibration Immunity:
Vibration: 5g, per IEC 60068-2-64.
Shock: 50g, 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
• Flexible RTD or linear resistance input ranges (any 100 ohm Pt RTD with 375-393 alpha)
• Space-saving 12.5mm (0.5 inch) unit with pluggable terminals for convenient wiring
• High accuracy, linearity, stability, and reliability
• Advanced analog signal conditioning ASIC eliminates digitization errors
• Low temperature drift (<80ppm/°C)
• Supports sink or source output wiring
• Programmable over/under-range limits
• Selectable upscale or downscale operation for sensor errors and lead-break detection
• NAMUR-compliant output loop current
• Shock (50g) and vibration (5g) resistant
• Mounts on Type T DIN-rail
• Wide ambient operation (-40 to 80°C)
• CE compliant. UL/cUL Class I Div 2, ATEX / IECEx Zone 2 approvals