Spirax Sarco M741 intelligent digital display works with TVA or TFA flowmeters for high-accuracy mass flow measurement of saturated steam or superheated steam (TVA only). Multiple installation options are available, including wall-mounted and panel-mounted configurations.

Features

• Combines with TVA/TFA to form a high-accuracy flow measurement system.

• Suitable for saturated steam or superheated steam (TVA only).

• Automatically stores the latest 65536 sets of historical data. The storage interval can be configured.

• Automatically plots historical curves for flow, temperature, pressure, and other parameters. The start and end coordinates can be configured.

• Real-time clock and scheduled automatic meter-reading functions simplify measurement management.

• Supports data communication with a host computer to create an energy metering network.

• Provides a 24V DC transmitter power supply with short-circuit protection for TVA/TFA, simplifying the system and reducing investment costs.

• Password protection prevents unauthorized personnel from changing configured data.

• No adjustable components such as potentiometers or coding switches are installed inside the instrument, improving vibration resistance, stability, and reliability.

• Specially designed WDT, power-on reset, and power-failure data protection circuits ensure normal operation when powered and prevent data loss during power failures. Data protection does not require a backup battery and remains effective for 10 years.

Options

• Wall-mounted version: Includes a stainless steel enclosure, weighs 8kg, and uses an external 220V power supply regulated internally to 24Vdc.

• Panel-mounted version: Installs on a control console or existing control cabinet, weighs 2kg, and is available as standard with a 220Vac power supply. 24Vdc is available as an option and must be specified when ordering.

Installation

• The panel-mounted instrument is secured to the instrument panel with two supplied mounting brackets.

• The wall-mounted version is secured to a wall or post with three M6 screws.

Technical Data - Input

M741 receives signals from TVA/TFA. TVA/TFA transmits measured data to M741 through digital communication. M741 accurately displays the data shown on the TVA/TFA LCD without any loss of accuracy.

Technical Data - Power Supply

Power supply	Power consumption
187-242V (±5%)	4W
Note: When powered by a UPS, a 10VA isolation transformer is recommended in the power supply circuit to prevent high-frequency signal interference.

Technical Data - Output

• 4-20mA active output (M741 supplies power externally): Maximum load impedance 600 ohms; data update period 0.5s.

• Communication interface: EIA RS-485 serial interface with optical isolation; communication rate selectable from 9600, 4800, 2400, or 1200 baud through the front panel; no parity, 8 data bits, 1 stop bit; twisted-pair cable transmission medium.

Environmental Conditions

Operating temperature	Relative humidity
0 ~ 50℃	0 ~ 85%

Ordering Information

Example: One Spirax Sarco M741 wall-mounted display, 220Vac.

Weight

Model	Weight (kg)
Wall-mounted version	8
Panel-mounted version	2