Thyracont VSP63D or VSR53D: specifying a gauge for machine controls

16 August 2026 · Technical review: 11 October 2026

A replacement gauge can fit the pipe and still give the control system the wrong information. When choosing a Thyracont VSP63D or VSR53D, check three things separately: the sensor, the vacuum connection and the electrical interface.

Start with the sensor principle

The VSP63D is a Pirani transducer with a measuring range of 1000 to 1 × 10⁻⁴ mbar absolute. The VSR53D combines piezo and Pirani measurement over 1200 to 1 × 10⁻⁴ mbar absolute.

Pirani measurement depends on gas properties. The combined sensor provides piezo measurement in the upper part of its range, but its lower-pressure Pirani response remains gas-dependent. State the gas and the normal working pressures instead of choosing only by the lowest number on the datasheet.

Check what “0–10 V” means

Both models provide a 0–10 V analogue output and RS485 communication. An analogue output range does not define its pressure conversion. The PLC or display must use the manufacturer’s transfer function and recognise any defined error indications.

For example, a control programme written for another manufacturer’s sensor may apply a different relationship between voltage and pressure. A plausible number on the screen is not proof that the conversion is correct. Include the existing sensor reference and control-system details in a replacement enquiry.

Confirm power, cable and connector

The listed models use a 20–30 V DC supply, a male 15-pin SubD connector and a DN16 ISO-KF vacuum connection. Confirm the pin assignments and cable specification rather than relying on connector shape. For digital integration, agree the communication settings and protocol as well as the physical RS485 connection.

Ask whether the quotation includes a power supply, cable and separate display or controller. If a local reading is required at the machine, discuss the optional display version before the order is placed.

Define switching behaviour

Both models have two potential-free relay outputs. Describe the required switching pressures and how the machine should respond during start-up, normal operation and a sensor fault. Integration and commissioning should confirm the intended response; the existence of a relay does not establish that an instrument is suitable for a safety function.

Check the installed measurement

Choose a connection point that represents the process pressure. Consider contamination and service access, and establish how readings will be checked during commissioning. Where traceable results are required, specify calibration at useful operating points.

A clear purchase specification brings these decisions together: exact model, gas, pressure range, connection, power, output, cable and control requirements. It saves time for both the equipment supplier and the person connecting the instrument.

Discuss your equipment requirement

Compare the instruments in our gauge comparison table and include any controller or display in the same enquiry. For a quotation, send your requirements to Girovac or call 01692 660 117.