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We design and manufacture frame interval timing devices
What are frame interval timers (FITs)?
The best way to understand what a FIT device is, is by considering its application in collision investigation.
In this field, determining a vehicle's speed from a recorded scene involves measuring both the distance and the time it takes for the vehicle to travel from point A to point B. The FIT device plays a crucial role in measuring the time component of this equation. Essentially, it functions as a large, precise stopwatch, accurately measuring the time difference between individual frames of recorded video footage. This precise timing is critical for calculating the vehicle's speed with high accuracy.
Fig 1 - FIT device developed by the UK Home Office in 2016
The original FIT device was developed and supported by the UK government until 2022, when they discontinued its manufacturing and support. Benneman stepped in to take on the challenge of designing and producing a successor device, and now also provides calibration and support services for all Home Office legacy devices—one of which is shown in Fig 1—ensuring that these critical tools remain operational and accurate.
How are frame interval timers used?
Consider this simplified example of a vehicle collision at a traffic intersection monitored by CCTV cameras. The collision investigator needs to determine the speed of the vehicle captured in the recorded footage, as this could provide crucial information about whether an offense was committed. To do this, the investigator must calculate both the distance the vehicle traveled over a certain number of video frames and the time it took to cover that distance.
By analysing the CCTV footage and using fixed reference points like lamp posts and road markings, the investigator can accurately measure the distance the vehicle covered across specific video frames. To determine the time component, the investigator returns to the scene of the incident and places the FIT device in the same field of view as the CCTV camera that recorded the collision. Once the FIT device is activated, a short period of footage is recorded and later brought back to the office for detailed analysis.
This footage is then played back frame by frame, with the time displayed on the FIT device being noted for each frame. By analyzing a sufficient number of frames, the investigator can determine the maximum and minimum time intervals between individual frames. With this information, the investigator can accurately calculate the minimum and maximum speeds at which the vehicle may have been traveling at the time of the incident.
The FIT device's accuracy, supported by calibration from an ISO 17025 accredited test laboratory, makes it a reliable tool that can be used as supporting evidence in a UK court of law.
What makes our FIT devices stand out?
Their displays are exceptionally bright, even in broad daylight
One of the standout features of our devices is their exceptional brightness, even in bright sunlight.
By utilising some of the most powerful directional LEDs available, we've ensured optimal visibility while minimising peripheral distraction to passing traffic. Honestly, photos on a website simply don’t do it justice—you really have to see it in person to appreciate it.
Users can also adjust the display brightness according to the ambient light levels and the desired viewing distance, providing flexibility and clarity in any environment.
2. They reveal additional information about the camera being analysed
By incorporating an inverted duplication of LEDs on opposite sides of the display—both horizontally and vertically—we provide users with enhanced insights into the camera being analysed.
This setup ensures that, regardless of the camera's orientation or the direction of the rolling shutter, users can take precise readings from the top, bottom, left, and right of the display. By simply subtracting the reading on one side of the display from the opposing side, users can accurately determine the shutter type, direction, speed, and duration.
In this image, the display is cleverly split into two distinct halves, resembling two separate devices.
The primary side, highlighted in blue, enables measurements on the left and bottom of the display. Conversely, the secondary side, shown in yellow, facilitates readings on the right and top.
Around the perimeter, the display features the smallest measurement units in milliseconds, while the center prominently displays the largest units in seconds.
3. LEDs are internally hardwired and therefore permanently synchronised
The inclusion of a secondary set of LEDs brings several additional benefits that enhance the functionality of our devices. Most importantly, it allows users to take readings from one half of the display, even if the other half is obstructed or affected by excessive glare.
This duplication furthermore provides built-in redundancy, allowing the device to be used even in the unlikely event of a malfunction on either side of the display.
4. They're easy and inexpensive to maintain
Our devices are built with modularity at their core, ensuring that replacing broken or faulty components is both simple and cost-effective.
Using standardised parts, we can easily swap out a broken panel or a cracked frame, making repairs straightforward and affordable. Short of being completely destroyed, such as by fire, it’s highly unlikely that it can’t be economically repaired. Furthermore, because we design all our parts for easy manufacturing by independent third parties, you’ll never encounter issues with parts being discontinued.
This guarantees long-term support and parts availability, even as we move on to new generations of the product.
5. Their modular design makes them upgradeable for years to come
No matter how much effort we put into our designs, we recognize that perfection is elusive and that both our insights and those of our customers evolve over time.
By keeping modularity and backward compatibility at the forefront of our designs, we can continuously improve our products without the need for complete replacement. Upgrading to a brighter LED or a new display pattern is as simple as inserting a new PCB or changing the overlay.
We want you to feel confident in your purchase, knowing that you won't be left with outdated features just months after model improvements are released.
6. Less effort and lower cost when shipping the device for calibration
Sending equipment for calibration can be inconvenient and costly. To make this process easier, we've separated the critical timing component from the bulkier display part, creating two separate units: the Control Unit and the Display Unit.
When it's time for calibration, you keep the Display Unit along with its accessories and protective case. You only send the lightweight Control Unit, which weighs less than 100g and fits comfortably in a padded envelope.
This approach aims to save the hassle of recording, packaging and shipping the entire kit. It also reduces the cost of goods-in-transit insurance, which is often significant considering the weight and value of a typical kit.
Additionally, since there are no hazardous batteries to declare, sending the Control Unit abroad for its periodic calibration becomes simpler and more affordable.
7. No device downtime during the calibration period
Our unique modular approach allows us to offer additional benefits, like our 'No Downtime' package, which is designed to eliminate concerns about calibration expiry and device downtime.
A few weeks before your device requires calibration, you'll receive a calibrated and certified replacement Control Unit in the mail. Simply place your current device into the provided padded, self-addressed, and pre-paid envelope, and drop it into the nearest post box or hand it to a Royal Mail collector.
This ensures you always have a calibrated FIT device without the need to remember or schedule periodic calibrations.
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