There are many kinds of gauges. There are three types of gauges available: Analog, Digital, and Pneumofathometer models. You need to find the right gauge for your diving needs. It is important to calibrate your gauge at all altitudes for safety decompression.
Analog gauges
Analog gauges used for gauge diving are useful in helping divers determine the depth of water. They work by having a needle pivot around a graduated scale to indicate the depth. These gauges can be worn on a wrist or integrated into the dive computer. Although they are more reliable than the digital gauges, analog gauges can still be used. One advantage of using an analog gauge is that you will never run out of batteries.
The gauge's front is simple to read. The gauge has numerical increments that range from 10' to 40’ and 20' up to 150'. The gauge also features a pressure gauge. It displays pressure from 0 to 5000 psi. The red screen represents reserve air, while green indicates main air.
Digital models
Divers want to dive long and deep. A digital gauge will not help them achieve this. Temperature changes can affect the pressure difference between the gauge's water and the ambient. A mechanical gauge is safer than an electronic one. In addition to keeping track of your dive time and depth, the gauge will calculate your Nitrogen retention and help prevent decompression illness.
There are two basic types digital gauge diving computers. The hose connection is a basic method that uses a hose. This hose connects the dive computer with the high-pressure port of the first stage. Wireless mode, however, connects the first stage with an electronic transmitter. This type is also available in console and wrist-mounted models.
Pneumofathometers
Pneumofathometers can be used to measure the depth of air that is supplied to divers. These devices measure the surface pressure of air and indicate the depth either in feet or meters. In the past, these devices were mounted on the hand-cranked air pump that supplied breathing air to the standard diving suit. The air supply was completely free-flowing, and there was no back-pressure.
Gauge diving is for divers who wish to use a gauge. A gauge should be able to read between 130 and 160 percent the maximum operating pressure of the diving system. This range should be adequate for systems that operate at 3,000psi.
Submersible pressure gauges
A submersible Pressure Gauge (SPG), is a device that allows divers to track their air pressure. It also displays the current depth and the direction the diver is moving. The SPG is attached to regulators via a high-pressure pipe. This arrangement reduces confusion and prevents the regulator from getting lost. A SPG measures the remaining air pressure per square inch. It is used to monitor your air supply while diving.
Scubapro produces an oil-filled analog depth gauge with a Bourdon tube design that measures to a depth of 200 feet. For greater versatility, it also includes a C1-compass that attaches to its console boot. This gauge is great for beginners as it is simple to use.
Compass
It is important to be able to read the compass easily when gauge diving. It should have adequate markings to suit your needs and be large enough to be readable underwater. A compass should have a bezel that contains compass headings organized in 30 degree increments, and indicator marks for every five degrees.
A side view window is an important feature of a compass that allows gauge diving. It lets the diver see the direction in which the compass point. This allows the diver even in complete darkness to follow the course of the compass.