Contact Us
Email Me

Tear Down
  Below are some photo's taken during post dive of PRISM Topaz # 14. This is an early unit and there are some upgrades that have not been applied to this unit yet, such as a larger scrubber and a cover for the back. Also, the attractive green color is no longer available. Because the PRISM is a modular system any upgrades from the factory can be applied to the earliest unit upgrading it all the way to the current Invader military unit. All photos are copyrighted to Mid Atlantic Research, Inc.

This photo shows the PRISM torn down for post dive. The counterlungs can have the inlet and outlet connected together to allow the cleaning solution to be sloshed around inside the lungs and hoses. The mouthpiece and hoses are in the scrubber bucket soaking in Betadyne. This allows easy cleaning of the entire breathing loop. Notice the drain valves on the bottom of the counterlungs which allow you to purge water during the dive if needed. The counterlungs are attached with Heavy Duty velcro and quick release buckles which makes tearing it apart for post diving really fast.

This is the rig torn apart on the table. Here you can see the stainless backplate, for now it is configured with the factory BC and Air2. Scrubber is double bagged and in the background the 19 cu ft. cylinders. You can see where the scrubber mates to the electronics head, and the three oxygen sensors.

Here's the top of the electronics compartment, notice how the cables are run between the head and backplate protecting them. The cable bulkheads are solid potted into the Electronics head so there is no chance for Helium to get into the cables. Here you can see the bulkhead connectors for primary, secondary and power switch, the connectors that go to the counterlungs, and the solonoid. The O2 solonoid is located outside the breathing loop to prevent any leaks or solonoid failure from filling the breathing loop inadvertantly with excess oxygen.

This picture is with the Battery cap removed. Inside is the 9 volt battery, under the top cap is the setpoint select ( .7, 1.0, 1.2, 1.3, 1.4) and primary calibration button. The lower cap has the secondary calibration cartridge which is user replaceable and allows calibration of the secondary display. The electronics are completely potted in case of flooding. Calibration is simple,

1. Fill the breathing loop with oxygen.

2. Push the primary cal button.

3. Tweak the three trim potentiometers to adjust the secondary meter.

Takes about a minute. The unit can be dove if the battery compartment floods by diving it manually. In the training course the student spends many hours diving manually.

Here it is with the bucket, scrubber and cylinders installed. A recent upgrade was the grip tape on the bucket. The bucket has no clamps or hardware it simply slides up and rotates on the locking lugs. The clear bucket is about 1/4 inch thick and I've seen one thrown repeatedly from a second floor balcony with no damage - it's incredibly tough! The regulators are off the shelf Scubapro MK2's allowing repair almost anywhere. Most LP hoses are standard length. Contents gauges are Scubapro mini gauges.

This is a fairly recent upgrade to the PRISM. The Head Down Display. This replaces the wrist mount MK15 style primary display and mounts on the mouthpiece. Here it is indicating Blue for Hypoxic, and this blue is definately an attention getter on a dive. This gives all the functionality of the wrist display, Led's for sensor or battery, and for Very Low, Low, OK, High, and Very High without having to look over at a wrist mount. It sits low in your vision and isn't distracting unless the VERY annoying Blue light is on, or it blinks the Red High above 1.55 PO2, most of the time it sits on the green which auto dims according to ambient light levels. The HDD can retrofit to any PRISM and the later SM1600's with SMI electronics.

The mouthpiece is standard SMI with brass rings to counteract the bouyancy of the hoses, which is very nice after being in the water for a few hours.

Here is the assembled unit, ready to dive. On the left you can see the secondary display which reads directly from the oxygen sensors. On the right is the on/off switch. Hdd, Secondary and power switch are solid potted with no thru holes, shaft seals or o-rings and cannot be flooded.

Here's a photo of the rig in the Kelp at Catalina Island.

Here's my PRISM on The IANTD Stand at DEMA 2003 in Miami Beach, Florida.

Below are some links to the PRISM Rebreather

Steam Machines the manufacturer of the PRISM

Jeremy has a tear down of his PRISM here

The Canadian distibutor of the PRISM Rebreathers Incorporated

The USGS using the PRISM

Dr. Bob at the Aquarium of the Pacific

Jeff Bozanic at Bikini Atoll

|Welcome| |Sodasorb| |PRISM Topaz| |Projects| |Contact Us| |About|