Photomultipler tubes in side-on and end-on housings.
PMTs are the most sensitive single channel detector we offer. Here, we show their performance with a Merlin Lock-in. The figures represents the performance levels that are fairly typical of our systems. The responsivity and dark current values of PMTs can vary by as much as a factor of 5 each, under identical bias and temperature conditions. Therefore, there may be a few tubes which will not reach these typical results. We offer room temperature end-on and side-on PMTs to cover the 160 to 1100 nm range.
We do not usually calibrate PMTs, since the long term stability is not adequate for this purpose. You can calibrate Merlin PMT systems with a standard lamp, or transfer calibration from a Silicon Detectors for Merlin Radiometer, provided care is taken in selecting the operating conditions.
Use any chopping frequency between the 8 and 1100 Hz limits of the Merlin Lock-in. The PMTs will comfortably follow any signal within these limits, transimpedance amplifier bandwidth allowing. Let the noise levels and the desired speed of data collection guide your chopping frequency and time constant selections. We find that frequencies equal to 1.5 or 1.75 times the line frequency and 0.3 to 3 second time constants work very well for low light levels.
We offer two PMT packages for Merlin: an end-on and a side-on system. Each Package Includes:
To Complete the System, Please Order the Following, Separately: