Honeywell TN3801 Temperature Transmitter

Overview

The TN3801 is part of Honeywell's smart temperature transmitter family, engineered for reliable and accurate temperature monitoring in industrial processes. It is housed in a compact, head-mount enclosure that fits into standard connection heads (DIN form B). The transmitter supports a wide range of temperature sensors and provides a linearized 4-20 mA output proportional to the measured temperature. Digital communication via HART protocol allows remote configuration and diagnostics.

Key Features

• Universal Input: Accepts Pt100 (2-,3-,4-wire), thermocouples (J, K, T, E, N, R, S, B), mV, and resistance signals.

• Output Signal: 4-20 mA analog with superimposed HART digital communication (revision 7).

• Accuracy: ±0.1% of span for RTD, ±0.2% for thermocouple (including cold-junction compensation).

• Isolation: 1500 V AC galvanic isolation between input, output, and power.

• Configuration: Local via push-buttons or remote using HART communicator or PC software (Honeywell SCT).

• Diagnostics: Sensor break detection (upscale/downscale configurable), transmitter self-test.

• Power Supply: 8-35 V DC (polarity protected).

Technical Specifications

• Input Range: RTD: -200°C to 850°C; Thermocouple: -200°C to 1820°C (type-dependent).

• Ambient Temperature: -40°C to +85°C.

• Storage Temperature: -50°C to +90°C.

• Humidity: 0-100% RH (non-condensing).

• Response Time: < 500 ms (typical).

• Dimensions: Ø44 x 22 mm (head-mount).

• Weight: 50 g.

Functional Description

The TN3801 measures the sensor signal, linearizes it according to the selected sensor type, and drives the 4-20 mA loop. The HART protocol enables digital communication over the same two wires, allowing readout of process variable, configuration of parameters (sensor type, range, damping), and diagnostics. The transmitter features a 16-bit A/D converter and a microcontroller for precise linearization and cold-junction compensation. It also includes a user-configurable sensor offset correction.

Applications

• Chemical and petrochemical plants.

• Oil and gas refineries.

• Power generation (boilers, turbines).

• Food and beverage processing.

• Pharmaceutical manufacturing.

Installation and Configuration

The transmitter is installed in the connection head of a temperature sensor (thermowell or thermocouple). Wiring is straightforward: connect the sensor wires to input terminals and loop power to output terminals. Configuration can be done using Honeywell's SCT (Smart Configuration Tool) software or any standard HART handheld terminal. The device supports burst mode and multivariable data transmission.

Certifications

• CE, ATEX, IECEx, FM, CSA for hazardous areas (intrinsic safety).

• RoHS compliant.

• Marine type approvals (DNV, ABS) available.

Note: This document provides technical information only; refer to the Honeywell TN3801 data sheet for complete specifications.