Centronics Photomultipier Tube (PMT): Model: 428 3SA

About this Centronics Photomultiplier Tube

• Photomultiplier length 14.5cm (including pins)
• Photomultiplier diameter 5 cm (front)
• Photomultiplier weight 146 g
• Photomultiplier in original box weight 672 g
• Box says: Type: P4823 SA
• Box says: Serial No.: 7122 – 214
• Box says: White Light Cathode Sensitivity: 265 micro Amps/Lumen
• Box says: Tested at: 0.01 Lumen
• Box says: Overall Voltage 1180 & Dark Current 4.0 nano Amps
• Box says: Wavelength Sensitivity: Blue (88), Red (1430), IR (183), 848 nm (19.0)
• Box says: Disposal List No. 3064, Item No. 309, Voucher No. 88/1638
• Box size 27 cm long x 14 cm wide x 15 cm high
• Writing on the tube says: Centronic, Type P482 3 5A, Serial 7122-214
• Writing on the tube says: Twentieth Century Electronics Ltd, New Addington, Croydon, 0BG, England
• No cables or instructions provided
• N.B. if the buyer lives outside the UK then they are responsible for any customs duty/import tax
• For any returns the buyer pays for repackaging and postage

Additional Information:

• Never owned a photomultiplier tube before – well this is your chance, at an affordable price!
• Photomultiplier tubes are used to detect single photons of light in applications like Astronomy, optical scintillation from cosmic ray air showers etc. A photon coming in the front end, knocks off an electron from the photocathode and the high voltage along the length of the inside of the tube cause it to accelerate and collide with some charged plates (dynodes), each time multiplying (e.g. 100 million times) the number of electrons knocked off/cascaded until you get a measurable signal at the far end of the tube, on the anode. The tube does not produce an image but instead measures the light flux from all the photons hitting the front of the tube.
• This particular photomultiplier tube has a good red and near IR sensitivity, so in astronomy would be used for looking at faint cool stars. It has a good time resolution as well, so you can easily get a resolution of 1/1000^th sec or faster if you have the right recording equipment. High time resolution applications in astronomy might be lunar occultations for measuring the angular diameters of stars, the separation between doubles stars. It could also be used for measuring optical flashes from pulsars, or even in optical SETI work for nanosec duration light pulses.
• Warning never point a powered-up photomultiplier at a bright light source as this will overload the tube and cause permanent damage.
• This photomultiplier tube would be suitable if you have an existing photometer which needs a replacement tube of this type. It might be useful for schools or university labs for education purposes on demonstrating the detection of single photons – but you will need to build the relevant circuitry. It could also look nice in a museum of science equipment/experiments, or given a suitable support mount would make a nice piece for a display cabinet in an art gallery.
• The photomultiplier tube will be sent by Royal Mail recorded delivery, and will have two protective layers – the original box with foam fitting around the tube. Then a second bubble wrap layer around the outside of the original box. Hopefully this will be enough to protect the tube in transit. As the tube was bought from a surplus store and appears to have been checked at the time of purchase, it should still work, even after 3 decades – however the seller has been unable to test it for sure.
• Two of the images on show on this posting is in 3D – you need to use stereo anaglyph glasses to see it – put a red filter over the left eye and a blue/green filter over the right eye. Best viewed in a dark environment without any reflections on the screen.

Enjoy!