Photon counting head
The H7421 series is a photon counting head device containing a metal package photomultiplier tube having a GaAsP/GaAs photocathode and a thermoelectric cooler. The thermoelectric cooler reduces thermal noise generated from the photocathode which also offers a high quantum efficiency, allowing measurement to be made with a good S/N ratio even at very low light levels. The H7421-40 has high sensitivity on wavelength from 300 nm to 740 nm. The H7421-50 is sensitive over a wide spectral range from 380 nm to 920 nm. The photomultiplier tube is maintained at a constant temperature by monitoring the output from a thermistor installed near the photomultiplier tube and regulating the current to the thermoelectric cooler.
|Photocathode Area Shape||Round|
|Photocathode Area Size||Dia.5 mm|
|Wavelength (Short)||300 nm|
|Wavelength (Long)||740 nm|
|Wavelength (Peak)||580 nm|
|Dimension (W x H x D)||56 x 36 x 104 mm|
|Input Voltage||+4.5 to +5.5 V|
|Max. Input Voltage||6 V|
|Max. Input Current||50 mA|
|Count Linearity||1.5 x 106 s-1|
|Dark Count Typ.||100 s-1|
|Dark Count Max.||300 s-1|
|Pulse-pair Resolution||70 ns|
|Output Pulse Width||30 ns|
|Output Pulse Height Min.||3 V|
|Output Pulse Height Typ.||3.6 V|
|Recommended Load Resistance||50 Ω|
|Signal Output Logic||Positive logic|
|Operating Ambient Temperature||+5 to +35 ℃|
|Storage Temperature||-20 to +50 ℃|
It looks like you’re in the . If this is not your location, please select the correct region and country below.
You're headed to Hamamatsu Photonics website for U.K. (English). If you want to view an other country's site, the optimized information will be provided by selecting options below.
For modern websites to work according to visitor’s expectations, they need to collect certain basic information about visitors. To do this, a site will create small text files which are placed on visitor’s devices (computer or mobile) - these files are known as cookies when you access a website. Cookies are used in order to make websites function and work efficiently. Cookies are uniquely assigned to each visitor and can only be read by a web server in the domain that issued the cookie to the visitor. Cookies cannot be used to run programs or deliver viruses to a visitor’s device.
Cookies do various jobs which make the visitor’s experience of the internet much smoother and more interactive. For instance, cookies are used to remember the visitor’s preferences on sites they visit often, to remember language preference and to help navigate between pages more efficiently. Much, though not all, of the data collected is anonymous, though some of it is designed to detect browsing patterns and approximate geographical location to improve the visitor experience.
Certain type of cookies may require the data subject’s consent before storing them on the computer.
This website uses two types of cookies:
There are two ways to manage cookie preferences.
If you wish to restrict or block web browser cookies which are set on your device then you can do this through your browser settings; the Help function within your browser should tell you how. Alternatively, you may wish to visit www.aboutcookies.org, which contains comprehensive information on how to do this on a wide variety of desktop browsers.
Occasionally, we may use internet tags (also known as action tags, single-pixel GIFs, clear GIFs, invisible GIFs and 1-by-1 GIFs) at this site and may deploy these tags/cookies through a third-party advertising partner or a web analytical service partner which may be located and store the respective information (including your IP-address) in a foreign country. These tags/cookies are placed on both online advertisements that bring users to this site and on different pages of this site. We use this technology to measure the visitors' responses to our sites and the effectiveness of our advertising campaigns (including how many times a page is opened and which information is consulted) as well as to evaluate your use of this website. The third-party partner or the web analytical service partner may be able to collect data about visitors to our and other sites because of these internet tags/cookies, may compose reports regarding the website’s activity for us and may provide further services which are related to the use of the website and the internet. They may provide such information to other parties if there is a legal requirement that they do so, or if they hire the other parties to process information on their behalf.
If you would like more information about web tags and cookies associated with on-line advertising or to opt-out of third-party collection of this information, please visit the Network Advertising Initiative website http://www.networkadvertising.org.
We use third-party cookies (such as Google Analytics) to track visitors on our website, to get reports about how visitors use the website and to inform, optimize and serve ads based on someone's past visits to our website.
You may opt-out of Google Analytics cookies by the websites provided by Google:
We inform you that in such case you will not be able to wholly use all functions of our website.