There are commercial, calibrated, hydrogen detectors, such as those from GasSensing or from Mcmaster-Carr, but you'd have to check with the supplier or manufacturer to determine if the other gases give a false reading, or, particularly silanes, poison the sensing element.
You can also make your own device using a sensing element, such as SGAS701 from Renesas, or, for US$5, the Hydrogen Gas Sensor - MQ-8 from SparkFun.
Be aware of some limitations of these sensors:
- Those catalytically measuring the heat generated from hydrogen combustion require oxygen in the stream.
- Some gases, such as silanes, may poison the sensor or build up a coating on it preventing gases from contacting it.
- Other gases, such as methane, $\ce{CH4}$, may give false readings.
You likely will need to contact the vendor's support for specifics; the online information, sch as that for the ATI electrochemical sensor, does not cover the specifics of your situation.
BTW, you might mention the desired accuracy and repeatability for these measurements.