HM – Head Mounted Transmitter
Overview
The Head Mounted Transmitter (HMT) is a compact, smart signal conditioning device designed to be installed directly into the connection head of a Temperature sensor. It is primarily used to convert RTD (Resistance Temperature Detector), Thermocouple (TC), resistance, or millivolt (mV) signals into a standard two-wire 4–20 mA analog output. This conversion allows reliable, noise-immune signal transmission over long distances, making the HMT an essential component in modern industrial Temperature measurement systems.
Working Principle
The transmitter receives a low-level signal from a Temperature sensor (RTD or thermocouple), amplifies and linearizes the signal, and then converts it into a stable 4–20 mA current signal. This signal can then be transmitted to a control room, PLC, or DCS for monitoring and control. The built-in cold junction compensation ensures accurate thermocouple readings, while PC-based configuration allows flexible setup and customization.
Key Features
Signal Conversion: Converts RTD, Thermocouple, resistance, or voltage inputs to 4–20 mA analog output
High Accuracy: ±0.1% Full Scale (FS) for precise measurement and control
Input Types Supported:
2 types of RTD input
8 types of Thermocouples (e.g., J, K, T, E, N, R, S, B)
Cold Junction Compensation: Built-in for accurate thermocouple performance
Smart Configuration: Setup and parameterization via PC software
Linear Measurement Options: Supports Temperature-linearity, resistance-linearity, and voltage-linearity
Alarm Functionality:
Outputs 3.9 mA or 22 mA in case of sensor failure or open circuit
Optional KH213 smart model for enhanced diagnostics
Saturation Current Range: 3.9 mA (low), 20.5 mA (high)
Temperature Range:
Operating: -40°C to +85°C
Storage: -40°C to +100°C
Compact Design: Easily fits into standard DIN connection heads (e.g., Form B)
Applications
- Industrial Temperature Control
- Power Plants and Utilities
- Oil & Gas Refineries
- Chemical & Petrochemical Plants
- Pharmaceutical Manufacturing
- Food & Beverage Processing
- HVAC & Building Automation
- OEM Equipment Integration
