How to Choose the Right Clock
There are many things to consider when choosing the right clock for your particular application. Here are a number of points that you will want to think about before deciding on a product that suits your needs.
Viewing Distance/Size
When choosing a clock and selecting the correct size for your space is critical. We publish a recommended viewing distance for all of our clocks as listed below and would suggest measuring your space to ensure that you get the correct size digital clock for the space and application you need.
Synchronisation
All of our clocks can work as standalone devices but for applications where time is absolutely critical or even if you want to remove the need to ever have to adjust the time on your clocks system, a synchronised solution is recommended.
In most synchronised clock installations NTP can be used which is a network protocol that allows various network client devices (such as Wharton digital clocks) to synchronise to an NTP server which would typically receive its own time via a GPS receiver. This allows all clocks on the network to show the same highly accurate time as provided by the NTP server.
NTP
NTP and SNTP are standard network protocols used for synchronising devices over a network or the internet. Most modern electrical devices that automatically show the correct time obtain this information from an NTP server. This might be a local NTP server in some cases or, more commonly with consumer devices, it will be an online NTP server. The NTP server will itself have an extremely accurate time source so that it can send the correct time information to other devices on request.
Some common examples of devices that tend to be synchronised via NTP would be phones, computers, CCTV systems, access control systems and of course clocks. The time sent by the NTP server will always be Universal Time (UTC) and any local time offsets that might be required for the specific timezone would be calculated by the device. Any device being synchronised in this way is typically referred to as an NTP client.
External NTP Servers
This could be used to describe any remote NTP servers that are available for public use online such as those from the NTP Pool Project in the UK or NIST in the US. Typically there would either be a direct IP address available or a domain name that in some cases will automatically direct any requests to one of a number of NTP servers. It’s worth noting however that many NTP clients (including any Wharton clocks) can only use a specific IP address and not a domain name.
External NTP servers are useful, readily available services that can be used with no additional hardware expense although there are a number of downsides to using this method. Addresses can go down for maintenance or without any warning at all due to service disruptions. A fixed NTP server IP address might even be changed entirely leaving your devices unsynchronised until this is spotted.
Intrernal NTP Servers
An internal NTP server could be a dedicated hardware device or even an existing server set up to act as an NTP server. Having your own internal NTP server will give you complete control in ensuring that your organisation has a reliable time source available at all times for any of your NTP clients. It will also significantly reduce any external traffic or even eliminate it completely assuming it has its own time source such as a GPS receiver, a highly accurate source of time regardless of global location.
Redundancy
Where accurate timing is extremely important you may have a need for a redundant system to insure that your entire system doesn’t lose synchronisation should there be an issue with the NTP server you are using. Many NTP clients including all of our Wharton network Digital Clocks and World Timezone Clocks are capable of looking to multiple NTP server IP addresses for synchronisation. Our recommendation for an optimal fully redundant system is to install two internal NTP servers giving you maximum control over the system with a built-in fail-safe, should one of the NTP servers fail or have an issue. It would of course be possible to program and mix of internal or external NTP server IP addresses though should you so wish.
Functionality
Time HH MM SS, Day, Start Stop, Multizone locations
Do you need to show the time, date, temperature or all 3? Are you looking for a count-up or countdown timer? Wharton Electronics offers solutions that cover all your needs.
If you are looking for something in particular but can’t find it on the site then please do get in touch. We may be able to make some suggestions or even design a unique custom product to fit your requirements.
Installation (case type)
From wall mounted to flush mounted or ceiling suspended options, indoor, outdoor or special environment options, we should have a product that suits your particular needs. Our standard indoor clocks come in many different case type options suitable for installation in a number of different ways and we also offer IP65 options for outdoor use or use in special environments as well as stainless steel clocks designed for cleanroom type applications.