TTR 101 Vacuum Gauge Troubleshooting Guide

<ST>Red is always on, abnormal output. Check for poor contact between electronic unit and sensor connection

<ST>The red constant light capacitive sensor is damaged and needs to be replaced

<ST>Red constant on EEPROM error, power off and restart. If it still exists, repair is required

<ST>The red constant light electronic unit is incompatible with the sensor. Replace the sensor or the entire transmitter

Continuous low output signal. Optical window or sensor contamination. Clean or replace sensor

The switch value does not operate and the set point is incorrect; Improper hysteresis setting, readjust SP1/SP2; Check the triggering mode of high and low points

7.2 Testing Pirani Sensor (Filament)

If you suspect a Pirani sensor malfunction, remove the sensor (see 7.3) and measure the corresponding pin on the electronic unit side with an ohmmeter (as shown in the manual):

Normal resistance: 40 ± 1 Ω

Pollution or partial short circuit: ≥ 40 Ω (may be higher)

Pollution or partial open circuit: ≤ 40 Ω

Filament burnout: ∞

Any situation exceeding 40 ± 1 Ω requires replacement of the sensor and cannot be repaired.

7.3 Steps for replacing sensors

Remove the transmitter from the vacuum system (see next section).

Use a hex wrench (AF 2) to loosen the hex socket screw between the electronic unit and the sensor.

Pull the sensor out of the electronic unit without twisting.

Insert a new sensor (also without twisting) and tighten the screw (torque of approximately 0.5 Nm).

Attention: After replacing the sensor, it is necessary to perform atmospheric pressure adjustment and high vacuum adjustment again.

Precautions for dismantling and returning to the factory

8.1 Disassembly steps

Release the vacuum system to atmospheric pressure.

Turn off the transmitter power.

Disconnect the sensor cable.

Remove the transmitter from the vacuum system and immediately install the protective lid.

8.2 Pollution Declaration

If the transmitter has been in contact with hazardous substances (radioactive, toxic, corrosive, biological hazards, etc.), a Declaration of Contamination must be filled out before returning to the factory, and downloaded from the Leybold website, filled out, and attached to the packaging. Devices without a declaration will be returned or incur additional cleaning fees.

Maintenance cycle and spare parts recommendations

Calibration cycle: It is recommended to perform zero point (ATM and HV) adjustment once a year.

Cleaning: If measuring gases containing dust, it is necessary to regularly clean the sensor inlet; You can use a soft brush or compressed air.

Spare parts: It is recommended to stock 1-2 sensors (please consult Leybold for part numbers) for quick replacement.

Repair: Any internal repairs (except for sensor replacement) must be carried out by authorized Leybold personnel, otherwise the warranty will be invalidated.

Precautions for replacing old models

If you are using an old THERMOVAC (such as TTR 91, TTR 96, etc.) or other brand vacuum gauge, please note when replacing it with TTR 101:

Output characteristics: TTR 101 outputs logarithmic signals ranging from 0 to 10.23 V, with a pressure voltage relationship of 1.286 V/decade. The old model may output 0~10 V linearly or with different slopes, and the calibration curve needs to be reconfigured in the controller.

Switching logic: default low point trigger (closed when pressure is below threshold), old systems may use high point trigger. PLC logic can be changed or modified through Profibus or on-site programming.

Identification resistor: TTR 101 provides a 71.5 k Ω identification resistor for the controller to automatically identify the range. Ensure that the controller supports reading the resistor.

Flange size: TTR 101 standard is DN 16 ISO-KF. If the old system uses DN 25 KF or other specifications, an adapter or flange replacement is required.

Profibus integration: The TTR 101 PB requires a GSD file, which can be downloaded from the Leybold website. The node address is set through a dip switch (MSD/LSD) rather than software.