TT334: Potentiometer / Thermistor Input, Four-Wire Transmitter

The TT334 model is a space-saving four-wire transmitter that isolates and converts a resistive sensor input to a proportional control signal. DC current and voltage output are both supported on a single model. An optional DIN rail bus can deliver primary or redundant power to multiple units without wiring.

High-voltage isolation separates the input from the output circuit. Isolation protects from surges, reduces noise, and eliminates ground loop errors.

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.

Performance Specifications

IMPORTANT: To prevent damage or errors from grounded PCs and surges, Acromag strongly recommends the use of their USB-ISOLATOR when configuring a TT330 Series transmitter.

USB Interface

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.

Maximum Cable Length: 5.0 meters.

Driver: Not required. Uses Windows HID drivers.

Input

Default Configuration: Pot/slidewire, 0% to 100% input, 4-20mA output, downscale break detect, medium filter.

Input Configuration:
Two- or three-wire sensor input connections.
User-configurable thermistor linearization table has preset curves for resistances below at 25°C.
Programs in °C, °F, °K, or ohmic integer values only.

Input Ranges
Input  Type                             Input Range                                     Accuracy
Potentiometer                  0 to 100% (100 to 100KΩ)         < ±0.01% of span
Rheostat                         100 to 1MΩ                                          < ±0.5% of input
Thermistor 2252Ω       -40 to 100°C (-40 to 212°F)           < ±0.05°C (±0.09°F)
Thermistor 2752Ω       -40 to 100°C                                       < ±0.05°C (±0.09°F)
Thermistor 2795Ω       -40 to 100°C                                       < ±0.05°C (±0.09°F)
Thermistor 3kΩ            -40 to 100°C                                       < ±0.05°C (±0.09°F)
Thermistor 5kΩ            -40 to 100°C                                       < ±0.05°C (±0.09°F)
Thermistor 10kΩ         -40 to 100°C                                        < ±0.05°C (±0.09°F)
Thermistor 30kΩ         -40 to 100°C                                        < ±0.05°C (±0.09°F)
Custom thermistor    100 to 1MΩ                                           < ±0.5% of input

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 on thermistor or rheostat inputs. Downscale only on potentiometer/slidewire inputs.

Excitation Voltage
Thermistor/rheostat: 1.25V DC, typical.
Potentiometer: 0.3V DC, limited to 3.35mA, typical.

Output

Output Range:
Range                    Over-Range                 Resolution
±10V                            ±10.5V                       1 part in 62558
±5V                               ±5.25V                      1 part in 31278
0 to 10V              –0.5527 to +10.5V        1 part in 59293
0 to 5V              –0.27634 to +5.25V        1 part in 60414
±20mA                        ±21mA                      1 part in 62400
0 to 20mA          –1.1054 to 21mA          1 part in 58732
4 to 20mA          –1.1054 to 21mA          1 part in 46984

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.

Output Load
Voltage output: 1K ohms minimum.
Current output: 0-525 ohms.

Output Response Time (for step input change)
No filter: 21ms Medium filter: 150ms.
Low filter: 40ms High filter: 1200ms.

Output Ambient Temperature Drift
Better than ±80ppm/°C (±0.0080%/°C).

Environmental

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), 1.3W maximum.

Isolation: 1500V AC peak. 250V AC (354V DC) continuous isolation between input, output, and power (3-way).

Shock and Vibration Immunity
Vibration: 4g, per IEC 60068-2-6.
Shock: 25g, per IEC 60068-2-27.

Approvals
CE compliant. Designed for UL/cUL Class I Division 2 Groups ABCD. ATEX / IECEx certified Zone 2. II 3 G Ex nA IIC T4 Gc -40°C < Ta < +80°C.

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.

Physical

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: 17.5 x 114.5 x 99.0 mm (0.7 x 4.51 x 3.90 inches).

Shipping Weight: 0.22 kg (0.5 pounds) packed.