EPRO MMS6418 Dual-Channel Measuring Amplifier

Overview

The EPRO MMS6418 is a dual-channel measuring amplifier designed for precise expansion measurement in machine monitoring systems. It forms part of the MMS 6000 series, ideal for monitoring machinery such as turbines, compressors, and other rotary systems. By connecting to inductive displacement sensors like PR 9350 and PR 6418/.., the MMS 6418 measures both absolute and relative expansions across two independent channels.

The MMS6418 ensures reliable data acquisition by utilizing a wide signal frequency range, with channel 1 covering up to 100 Hz and channel 2 up to 10 Hz. It also features independent zero point adjustment and zero shift, providing exceptional flexibility for various applications. The system operates in harsh industrial environments with robust noise suppression capabilities.

Key Features

Dual-channel measurement: Separate channels for absolute and relative expansion measurements.
Wide frequency range: Channel 1 supports frequencies up to 100 Hz, and channel 2 up to 10 Hz.
Flexible zero adjustment: Independent zero point and zero shift for easy calibration.
Enhanced noise suppression: Balanced sensor supply grounded for industrial noise filtering.
Advanced interfacing: RS 232 interface for configuration, RS 485 for connection to analysis systems or host computers.
Suitable for various applications: Ideal for steam, gas, and water turbines, compressors, and turbo machinery.

Applications

Part of the MMS6000 machine monitoring system.
Connects to inductive displacement sensors like PR 9350 for absolute expansion measurements on channel 1.
Measures relative expansions with PR 6418/.. on channel 2.
Useful in industries such as turbines, compressors, fans, and centrifuges.
Supports machine protection systems for improving efficiency, safety, and operational lifespan.

Technical Specifications

Sensor Inputs

Specification	Details
Channel 1 (Absolute Expansion)	Half bridge circuit or differential transformer
Channel 2 (Relative Expansion)	Differential transformer
Signal Input Type	Differential, galvanically isolated
Overload Protection	Short-circuit and open-circuit proof

Channel 1 – Absolute Expansion

Specification	Details
Max Input Voltage	3.6 V (Protected against overvoltage)
Nominal Input Voltage	2.5 Vrms
Input Impedance	200 kOhm
Measuring Frequency Range	0-100 Hz (-3dB)
Measuring Ranges	Depends on sensor type

Channel 2 – Relative Expansion

Specification	Details
Max Input Voltage	30 Vrms (Protected against overvoltage)
Nominal Input Voltage (PR 6418/01)	15-300 mVrms
Nominal Input Voltage (PR 6418/02)	15-400 mVrms
Input Impedance	200 kOhm
Measuring Frequency Range	0-10 Hz (-3dB)
Measuring Ranges	PR 6418/01 ±10 mm, PR 6418/02 ±20 mm

Sensor Supply (Channel 1)

Specification	Details
Carrier Frequency	4.75 kHz
Nominal Supply Voltage	4 Vrms
Permissible Load	120-600 Ohm
Output Characteristics	Balanced to ground, open-circuit, and short-circuit proof

Sensor Supply (Channel 2)

Specification	Details
Carrier Frequency	1.963 kHz
Nominal Supply Voltage	30 Vrms
Permissible Load	150 mA (Impedance 200 Ohm), 250 mA (Impedance 125 Ohm)
Output Characteristics	Balanced to ground, open-circuit, and short-circuit proof

Control Inputs

Specification	Details
Logical Binary Inputs	Used for various system control functions
Optocoupler Mode	Pre-alarm and main alarm configurations
Limit Value Multiplier	Adjustable in the range of 1.000 to 4.999
Key Pulse Input	1 pulse per revolution for system synchronization