Notice about maintenance service of ionization gauge (SH200, ST200)

We appreciate your business and look forward to serving you in the future.

1.Reason of notice
Over the past six months, several failures have occurred in which the filaments of ionization
gauges have failed to turn on. As a result of investigating the failure conditions and the
affected products, it was found that similar failures may occur in the following models and
serial numbers. The failure depends on the filament operating time, and the accumulated
operating time is about 500 days on average. This average days is based on 24 hours
continuous operation, so it can be expected to 1500 days if the gauge operate for 8 hours a
day.
Although the time to failure may be short or long depending on usage conditions, there is a
possibility of failure during use. So we offer a maintenance service for the affected products,
including those that are beyond the warranty period of one year. We will replace the
electrical parts in the gauge that are causing the problem with more resistant parts.

2.Affected models and serial number
　　　Model　　　　　　　S/N
　　　SH200-A　　　　　00001～03023
　　　SH200-R　　　　　00001～00400
　　　ST200-A　　　　　00001～00626
　　　ST200-R　　　　　00001～00174

3. Details of failure
An error occurs during or when the filament turn on, even though there is no fault with the
sensor. Replacing the controller improves the defect.

4. Causes and remedies
Failure of smoothing capacitor in filament drive circuit cause the filament error. There is no
safety problem caused by capacitor failure. The accumulated filament operating time is
around 500 days, and it has been found that vacuum gauges with a high operating rate and
continuously filament operation tend to fail. As a remedies, the relevant capacitor is replaced
with a more resistant parts.

5. About maintenence service
The applicable products will be taken back to our service center and the capacitor replaced
free of charge. After the parts have been replaced, the controller will be returned to you
after checking that the filament operation and the pressure indication values are
satisfactory. There is no need to return the sensor, so your vacuum condition will be
maintained.

6. Period of service
31 Nov 2024 - 31 Mar 2027

7. Contact
To receive this service, please contact your purchased route or our sales and service
offices.
Link for sales and serivce offices.
https://www.ulvac.co.jp/en/support_info/service/