The Spirax Sarco M741 intelligent digital display can be used with TVA or TFA flowmeters for high-precision metering of saturated steam or superheated steam (TVA only) mass flow. It offers diverse installation options, available in wall-mounted and panel-mounted configurations.

Features

• Forms a high-precision flow measurement system when used with TVA/TFA flowmeters.
• Suitable for saturated steam or superheated steam (TVA only).
• Automatically saves up to 65,536 sets of the latest historical data, with configurable saving intervals. Automatically plots historical curves for flow, temperature, and pressure; coordinate start and end points can be configured.
• Real-time clock and automatic timing meter reading functions bring convenience to measurement management.
• Can perform data communication with host computers to form an energy measurement network system.
• Provides +24V DC power supply (with short circuit protection) for the transmitter to power the TVA/TFA, simplifying the system and saving investment.
• Password settings prevent unauthorized personnel from changing configured data.
• No adjustable components such as potentiometers or coding switches are installed inside the instrument, thereby improving vibration resistance, stability, and reliability.
• Specially designed WDT circuit, power-on reset circuit, and power-off data protection circuit ensure normal instrument operation when powered on and prevent data loss during power outages. Power-off data protection does not require a backup battery, and the protection duration is 10 years.

Options and Appearance

• Wall-mounted type: Features a stainless steel meter box. Weight: 8kg. External power supply is 220Vac, internally regulated to 24Vdc for use.
• Panel-mounted type: Installed on a console or existing control cabinet. Weight: 2kg. Standard power supply is 220Vac; 24Vdc is optional (must be specified when ordering).

Installation

The panel-mounted instrument is fixed to the instrument panel via two mounting brackets (included). The wall-mounted type is fixed to a wall or column via three M6 screws.

Dimensions (mm)

Wall-mounted type

Technical Parameters

Input

The M741 signal comes from the TVA/TFA. The TVA/TFA uses digital communication to transmit measured data to the M741. The M741 can accurately display the data shown on the TVA/TFA LCD screen without any loss of accuracy.

Power Supply

Parameter	Value
Power Supply	187-242V 50Hz±5%
Power Consumption	4W

Power Supply Note

If using a UPS power supply, it is recommended to install a 10VA isolation transformer in the power supply circuit to prevent high-frequency signal interference.

Output

Parameter	Description
4-20mA (Flow Retransmission)	Active output (M741 provides external power) Maximum load impedance: 600 ohms Data update cycle: 0.5 s
Communication	Interface: EIA RS-485 serial interface (opto-isolated) Baud rate: 9600, 4800, 2400, or 1200 baud (selectable via panel) Format: No parity, 8 data bits, 1 stop bit Transmission medium: Twisted pair

Environmental Conditions

• Operating Temperature: 0 ~ 50℃
• Relative Humidity: 0 ~ 85%