There are various types of gauges available on the market. There are three main types: Analog, Digital and Pneumofathometer models. You need to find the right gauge for your diving needs. Also, calibrating your gauge is crucial for decompression safety, especially at high altitudes.
Analog gauges
Analog gauges are used to help divers gauge the depth of the sea. You can use them to indicate the depth by turning a needle around a graduated scale. These gauges are worn on the wrist or can be integrated into the dive computer. They are less accurate than digital gauges but more reliable than analog. The advantage to using an analog gauge is that it will never run out batteries.
The gauge's front is simple to read. It offers numerical increments in depth of 10'-40', 20'-40', and 20'-150'. The gauge also includes 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 often want to dive deep and stay for long periods of time. However, a digital gauge is not able to help them. Temperature variations can alter the pressure differential between the gauge (and the ambient water). A mechanical gauge is far safer than an electrical gadget. A gauge not only keeps track of dive time and depth but it also calculates Nitrogen retention and helps prevent decompression illness.
There are two basic types for digital gauge dive computers. The hose technique is the simplest. It uses a hose for connecting the dive computer to a high-pressure port on stage 1. The wireless mode connects to the dive computer using an electronic transmitter attached at the first stage. This type of computer can also be found in console and wrist-mounted versions.
Pneumofathometers
Pneumofathometers can be used to measure the depth of air that is supplied to divers. These devices measure surface air pressure and indicate depth in meters or feet. These devices were used to be mounted on an air pump that provided breathing air for standard diving suits. 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. A gauge with this range would suffice for a system that operates at 3,000 psi or more.
Submersible pressure gauges
A submersiblepressure gauge (SPG), allows divers to keep track and monitor their air pressure. It displays the current depth as well as the direction that the diver is moving. The regulator is connected to the SPG via a high pressure hose. This arrangement is useful for divers to avoid getting confused about the location of the gauge and helps prevent it from being lost. The SPG is a gauge that shows you the remaining air pressure in psi. It's useful for monitoring your air supply during diving.
Scubapro manufactures an oil-filled, analog depth gauge. The Bourdon tube design measures down to 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
The easiest compass for gauge diving to use is one that is easy enough to read. The compass should be large enough to be read underwater and be marked with the appropriate markings. You will want a compass that has a bezel with indicator marks at every five degrees and compass headings in increments of 30 degrees.
Side view windows are important for gauge diving. They allow the diver to see where the compass points. This allows the diver even in complete darkness to follow the course of the compass.