THERMOVAC MEMS Vacuum Gauge Guide

Disconnect the power and cables.

Use a special tool (hex wrench) to loosen the fixing screw between the sensor and the electronic unit.

Pull out the old sensor vertically and insert the new sensor (pay attention to the direction).

Retighten the screw (torque approximately 0.5 Nm).

After reinstallation, zero point adjustment must be performed.

Attention: After replacing the sensor, the calibration data of the transmitter may be lost. It is necessary to perform a complete ATM and HV adjustment.

9.3 Cleaning

If the sensor is contaminated with dust, it can be gently blown with dry compressed air or nitrogen. Avoid using liquid cleaning agents or contact with sensor surfaces. For severe pollution, it is recommended to replace the sensor.

9.4 LED ring status indication

Green constantly on: Normal operation, pressure within measurement range.

Green flashing: warming up or initializing.

Red constantly on: Sensor error (such as filament disconnection).

Red flashing: Communication error or set point out of range.

Precautions for replacing old models

If you are using the old THERMOVAC (such as TTR 90, TTR 100) or other brands (such as Pfeiffer, MKS, Granville Phillips) Pirani vacuum gauge, please note when replacing with TTR 91/911 series:

Output characteristics: Old models may output linear voltage (0-10V corresponds to 1e-4~1000 mbar), while TTR series outputs logarithmic voltage. The calibration curve must be reconfigured in the controller.

Power supply voltage: The TTR series supports 9~30 V DC and is compatible with most 15 V or 24 V systems. Check the power supply capability of the old system.

Cable: The TTR series uses RJ45 connectors, which may require adapters or reworked connectors. Leybold provides prefabricated cables (5-100m).

Flange size: TTR standard is DN 16 ISO-KF. If the old system is DN 25 KF or half "pipe, a variable diameter flange or special version (such as CF or NPT) needs to be ordered.

Digital communication: If the old system uses RS 485 or DeviceNet, TTR 911 SN/CN provides RS 232, EtherCAT or Profibus, which may require a protocol converter.

Set point logic: The default triggering method of TTR relay (low point triggering) may be opposite to the old system. You can change it to high point triggering in the settings or modify the PLC logic.

Ordering Information and Accessories

11.1 Transmitter model (some part numbers)

Model and Part Number

TTR 91 N, DN 16 ISO-KF 230035V02

TTR 91 SN, DN 16 ISO-KF, 2SP 230040V02

TTR 96 N, DN 16 ISO-KF, 2SP (coating) 230045V02

TTR 911 N, DN 16 ISO-KF, Equipped with display screen 89654V02

TTR 911 CN, DN 16 ISO-KF, EtherCAT, Coating 230701V02

TTR 911 SN, DN 16 ISO-KF, RS 232 89660V02

TTR 916 N, DN 16 ISO-KF, Equipped with display screen and coating 89656V02

11.2 Accessories

Connecting cables (FCC68 at both ends, 8-core shielded): 5 m (12426)、10 m (230012)、15 m (12427)、20 m (12428)、30 m (12429)、50 m (12431)、75 m (12432)、100 m (12433)

Spiral tube DN 16 ISO-KF (for flexible connections): 230082

Interchangeable sensor (TTR 916 N): 230650V02

Interchangeable sensor (TTR 916 CN): 230651V02