We recently took an in depth look at the sewer inspection camera; the different types of inspection and where and when the professional mighgt need one.
However, if you are in the market for buying one, (and none of the top 5 we recently reviewed tickled your fancy); this buyer’s guide will help you orientate what’s available so that you can buy with confidence.
Let’s take a closer look…
Sewer Camera Buying Guide
Based on the sewer camera description provided above, it is evident that this equipment is a composite made up of 3 linked parts; the miniature video camera, the fiberscope that also conveys electric cables, and the monitor hub that displays the images and video captured by the camera.
Miniature Video Camera
Its resolution is the most important consideration, with high-resolution miniature cameras being ideal for sewer pipe inspection.
This is because it enables the user to better visualize and identify the problem.
Moreover, high-resolution video cameras are best suited for troubleshooting corrosion (or corroded pipes), pipe misalignment, puncture (in pipes), breakage, off-grade pipe quality, cracks, and the most menacing root intrusion which allows plant roots to grow inside sewer pipes.
Regarding resolution appropriateness, the rule of the thumb is that the right resolution is any resolution that can capture videos whose image resolution is higher than the monitor display resolution.
This ensures the video displayed on the monitor is the highest quality video that it (monitor) is capable of presenting.
Another consideration is whether radio transmitters are fitted on the camera so that one can record how far the camera has travelled inside the pipe, as well as know the precise location of the camera.
This also allows technicians to accurately locate a defect in the pipe.
Even so, this requires the radio transmitters to be synchronized to an above-ground locator device that picks and locates the transmitted signals, hence allowing the technician to know exactly where to dig or locate the nearest test tee that allows him to access the faulty underground pipe.
Normally, these transmitters operate at a frequency of 512 hertz (Hz).
Also, the camera must be fully waterproof, and resistant to high fluid pressure that can be encountered in sewer systems.
This also means that the camera must be fitted well into the insertion probe so that high-pressure does not cause any detachment or leakage of sewer fluid into the fiberscope.
This construction aspect is usually determined by the camera housing with stainless-steel housing providing adequate pressure-resistance and water-proofing. Likewise, the material must be resistant to chemical degradation, especially sulfide corrosion.
The size of the camera is also another important consideration, as it not only determines the diameter of the insertion probe, but it also determines the minimum pipe width that the camera can inspect.
Normally, an inch-wide camera is considered ideal for inspection of sewer lines, though such a camera head cannot fit in plumbing lines whose width is less than 1-inch (in). In such a case, the alternative 6-millimeter wide camera can be used.
Type of camera head
Camera size is also related to another consideration, the type of camera head. There are 3 main types of camera heads; standard, pan-tilt, and self-leveling head.
The self-leveling and pan/tilt head allows one to have a full view of the pipe space in front of the camera, including pipe walls and behind corners.
The zoom capacity of a camera also needs to be considered, as it determines how detailed its images can be, as well as allows it to detect cracks and leaks that would otherwise have been missed by the naked eye.
Another related consideration is image rotation, which is determined by the ability of the camera to tilt or pan, as well as self-level. Moreover, self-leveling is an added advantage as it minimizes distortion of the video record being captured.
Lighting quality is another key consideration as it determines how well illuminated the pipe interior is. High-quality cameras allow one to adjust the light brightness.
This in turn requires the camera head to be affixed with high-grade LED lights whose lumen output can be adjusted based on the natural light inside the pipes.
The camera must also be able to record color videos as color variance in the image allows the technician to easily identify a pipe defect. Nonetheless, some budget models come with a black-and-white only video camera.
Lastly, some camera models are capable of recording their videos directly into their inbuilt storage device or a removable media, usually a memory card, instead of transmitting their images directly to the monitor hub.
This allows the user to engage in other activities as the camera views the interior of the pipe, and later on review the recorded inspection video.
This is the fiberscope and attached accessories including electric cables that deliver power to the camera and LED lights.
This probe needs to be flexible, though there are some models that come with rigid probes for inspecting short sewer pipes in the house.
There are 4 key characteristics that one must consider when choosing a probe, and they are:
This determines how far the inspection camera can reach inside the pipe, and as expected, it determines the usefulness of the inspection camera in different work settings.
Long probes can even allow one to view the entire pipe from one manhole to the adjacent manhole. Most commercial-grade sewer inspection camera come with probes that measure anywhere between 20meters and 120meters(m).
The long probes (50m or more) need to be wound on a reel, and this reel needs to have a strong stand that allows the user to easily wind and unwind the probe without the reel toppling over.
As mentioned earlier, the probe is used inside a highly corrosive environment that is sometimes characterized by high fluid pressures, and rapid pressure fluctuations.
This requires the probe to resist being pulled apart or torn by rapid pressure shifts; or being corroded and rendered unusable by hydrogen sulfide and other offensive highly-reactive chemicals in the sewers.
Most consumer-grade probes are made from PVC which are durable and tough enough for normal inspections.
Nonetheless, PVC probes can undergo rapid degradation if used in routine heavy-duty inspection work. In such circumstances, Kevlar braiding is recommended, as Kevlar -braided probes can withstand heavy-duty work.
This is because Kevlar is 500 percent more durable and tougher than steel.
Resistance to Degradation
This requires the probe to be water-proof and also withstand high fluid pressure and high concentration of corrosive chemicals.
Generally, a probe that can withstand 6 bars (87pounds per square-inch[psi]) of fluid pressure is considered adequate for normal sewer-line inspection.
This determines the pipe sizes that the probe can travel through, and in extension determines the pipe sizes that the camera can view.
Generally, the probe should be of equal diameter to the camera head so as to ensure that the camera can reach the smallest pipe possible.
Moreover, small-diameter probes are better at bend-negotiation as compared to their larger-diameter counterparts.
There are two main types of hubs; the small and portable hand-held hub and the large stationery monitor system.
Regardless of the type, their main component is the display screen. It also contains accessory devices such as a USB port, memory card slot, and keyboard. These features are described below:
It should be able to deliver high-resolution images. Apart from image resolution, the screen size also matters as large display screens allows one to view a clear zoomed-out and detailed image of the pipe interior.
Additionally, the screen should allow one to view it during daylight, and high-quality inspection camera models come with daylight readable monitors. Most of these monitors are LCD/TFT or LED monitors.
The display screen is part of an embedded computer system that allows for camera images to be viewed, saved, and the accompanying videos recorded for future review.
Nonetheless, the insertion probe needs to be attached to the monitor hub so that its fiber scope can relay the camera images to the computer.
In some models, the insertion probe terminates into a standard USB 2.0 or USB 3.0 which can be plugged into the USB port in the (monitor) hub.
This makes the insertion probe detachable, which also means that it can be used with different monitor hubs that have USB ports.
In some models, the anterior end of probe is soldered into the hardware circuitry of the hub, so that its fiberscope delivers its images to image-processing computer hardware that are supported by an accompanying image processing software installed in the computer.
This allows one to easily input instructions to guide the operations of the inspection camera. Likewise, it allows one to easily manage the functions of the hub.
The hub needs to be splash-proof and water-proof as it is used in an environment prone to fluid splashing.
Image Capture, Processing, and Storage
The inspection camera can capture images in different file formats, such as JPEG and PNG, which need to be readable by the monitor hub.
Likewise, the camera can capture images at pre-defined resolution. This camera functionality ensures that the user can define the image quality needed, as well as set the required image format.
These images can then be processed into different image formats or combined together to create a more holistic view of the pipe status.
These processed images need to be stored, and they can be stored directly to the internal storage drive of the monitor hub (which is usually very small), or into a removable media such as a memory card or thumb drive; and in some professional models, be sent over via the internet into a remote storage location.
Other Factors to Consider When Buying a Sewer Inspection Camera
Another factor that one must consider is the intended use of the camera as this determines the camera design that best suits the user needs.
The other main factor to consider is the cost, as one can only purchase a model whose price fits the available budget.
Other factors to consider are weight, size, build design, warranty, and availability of after-sale services. Likewise, one can consider the grip of hand-held monitor hubs.
Evidently, there are different models, sizes, types, and designs of sewer cameras, and their design quality and operational quality also varies.
This allows for these products to be rated so that high-quality and high-performance models can be identified.
For more information head to our latest review round up that focuses on 5 of the best sewer cameras available in the market today.