If you want to become a hyperbaric technician, you’ll need to pass a certification exam. The National Board of Diving & Hyperbaric Medical Technology administers the test, which has 120 questions and requires a passing score of 70%. Practice with the free Certified Hyperbaric Technologist practice test on PracticeTestGeeks (7 questions with answer explanations).
The certification exam for hyperbaric chamber operators typically consists of written and practical components. The fees associated with these tests vary by national boards.
The Certified Hyperbaric Technologist Test has 120 questions, takes about 2 hours and costs $150[1][2][3] (National Board of Diving & Hyperbaric Medical Technology, verified Oct 25, 2026).
Numbers in brackets link to the official sources listed under Sources & last verified. Dates that have passed are removed automatically.
| Item | Detail | Source · Verified |
|---|---|---|
| Number of questions | 120 multiple-choice or true/false questions[1] | National Board of Diving & Hyperbaric Medical Technology · Oct 25, 2026 |
| Time limit | 2 hours[2] | National Board of Diving & Hyperbaric Medical Technology · Oct 25, 2026 |
| Passing score | 70% correct (90%+ = With Distinction)[1] | National Board of Diving & Hyperbaric Medical Technology · Oct 25, 2026 |
| Exam fee | $150 registration fee + $25 background check ($175 total)[3] | National Board of Diving & Hyperbaric Medical Technology · Oct 25, 2026 |
| Retake fee | $50 per retest[3] | National Board of Diving & Hyperbaric Medical Technology · Oct 25, 2026 |
| Retake policy | 3-month wait after each failed attempt; after 2 fails, retake course and repeat internship[1] | National Board of Diving & Hyperbaric Medical Technology · Oct 25, 2026 |
| Validity | 2 years[1] | National Board of Diving & Hyperbaric Medical Technology · Oct 25, 2026 |
| Renewal | Every 2 years: 24 CEUs (12 Category A) + $75 fee + $25 background check[4] | National Board of Diving & Hyperbaric Medical Technology · Oct 25, 2026 |
| Delivery | Online, at Board-recognized testing centers[2] | National Board of Diving & Hyperbaric Medical Technology · Oct 25, 2026 |
| Eligibility | Qualifying license + NBDHMT-approved course + 480-hour internship (40 supervised)[1] | National Board of Diving & Hyperbaric Medical Technology · Oct 25, 2026 |
| Score release | Immediately at completion of testing[2] | National Board of Diving & Hyperbaric Medical Technology · Oct 25, 2026 |
| Registration deadline | At least 30 days before the exam[2] | National Board of Diving & Hyperbaric Medical Technology · Oct 25, 2026 |
Interactive Certified Hyperbaric Technologist Test resources on PracticeTestGeeks, free to start:
According to National Board of Diving & Hyperbaric Medical Technology, “The examination is taken online, involves 120 questions and has a limit of two hours.”[1]
Prepare for the Certified Hyperbaric Technologist Test exam with our free practice test modules. Each quiz covers key topics to help you pass on your first try.
These are practice questions written for this site, not questions from the real exam. Each explanation shows why the right answer is right and why the others are wrong.
Question: First aid for a suspected DCS or AGE victim before reaching a recompression chamber includes:
Answer: A. 100% normobaric oxygen, IV fluids, and supine positioning
Explanation:
The correct answer is 100% normobaric oxygen, IV fluids and supine positioning. High-flow oxygen helps wash inert gas out of bubbles and treats tissue that is short of oxygen. Fluids support circulation, and lying flat avoids a drop in blood pressure when the patient sits or stands.
Cold water immersion is wrong because it does nothing to reduce bubbles and can add cold stress to an unwell patient. Aspirin is wrong because the problem is gas in the vessels and tissue, not a clot that aspirin would treat. Rebreathing into a paper bag is wrong because raising carbon dioxide does not help bubbles and can make the patient worse.
Rule to remember: before recompression, give oxygen, support circulation, keep the patient flat and get them to a chamber.
Question: What is the significance of maintaining an 'oxygen use log' in a hyperbaric facility?
Answer: A. It tracks oxygen consumption for safety compliance, supply management, and regulatory documentation
Explanation:
The correct answer is that the log tracks oxygen consumption for safety compliance, supply management and regulatory documentation. Oxygen is both a treatment gas and a fire hazard, so a facility needs a running record of what it uses and what it has on hand. That record also shows inspectors and auditors that the facility is operating as it should.
The option limiting it to multiplace chambers using air tables is wrong because the log is about oxygen handling, not chamber type. The option limiting it to adverse events is wrong because a log that only records problems cannot show routine use or supply. The option calling it optional with no regulatory significance is wrong because logs support compliance.
Rule to remember: if oxygen is used, it is recorded every time, not only when something goes wrong.
Question: Henry's Law describes which physical phenomenon relevant to hyperbaric therapy?
Answer: B. Amount of gas dissolved in a liquid is proportional to its partial pressure
Explanation:
The correct answer is that the amount of gas dissolved in a liquid is proportional to its partial pressure. This matters in hyperbaric therapy because breathing oxygen at increased pressure raises the amount of oxygen dissolved in blood plasma, and it also explains how inert gas is taken up and later released from tissue.
Gas volume changing with temperature is wrong because that describes a different gas law, which links temperature and volume. Light refraction in water is wrong because it is an optics topic with no bearing on gas uptake. Heat transfer in gases is wrong because it describes thermal behavior, not dissolving.
Rule to remember: Henry's Law is about solubility. Higher partial pressure of a gas means more of that gas dissolved in the liquid.
Start with the official material. Download the Board's CHT Resource Manual from nbdhmt.org and read what it says about the exam and eligibility, so you know what you are working toward. Then use the practice sets to find where you are weak.
Take a set on hyperbaric physics fundamentals early, because gas laws underpin much of the rest. Move on to chamber operations, then fire safety and oxygen hazards and decompression sickness and gas embolism treatment.
After each set, read the explanation for every question you missed and write down the rule behind it in your own words. Retake the same set a few days later without notes and see whether the rule stuck.
Closer to test day, mix topics and practice finishing 120 questions inside 2 hours. Our questions are written by us and are not real exam questions, so treat them as practice for the topics, not a preview of the paper.
Certified Hyperbaric Technologist (CHT) is a recognized certification that validates a professional's ability to operate hyperbaric chambers and provide therapy to patients.
The CHT test includes both theoretical knowledge and practical assessments of your ability to work in a hyperbaric environment.
The certification process involves completing specific educational requirements, hands-on training, and passing a comprehensive exam.
Achieving CHT certification enhances job prospects, credibility, and professional development within the hyperbaric medicine field.
The CHT certification is recognized by various healthcare institutions and is required in many clinical settings.
Getting certified as a hyperbaric technologist can help you build your career in the medical industry. The certification process varies from one organization to the next, but typically involves both a written exam and a practical demonstration of your skills. The costs of certification can vary, but are generally low compared to other professions. You can learn more about the different certification paths and their requirements by contacting your local hyperbaric facility or checking with a national board.
The Certified Hyperbaric Technologist (CHT) or Certified Hyperbaric Nurse (CHRN) certification is administered by the National Board of Diving and Hyperbaric Medical Technology (NBDHMT). The CHT is a voluntary credential for professionals in hyperbaric medicine, and its validity is determined by the NBDHMT. The certification process includes a background check, examination fees, and the submission of competency checklists.
NBDHMT also requires CHTs to receive continuing education credits to maintain their certification. These can be earned through a variety of methods, including attending meetings and conferences. This training helps to keep technicians up-to-date on the latest safety protocols and equipment.
| Pros | Cons |
|---|---|
| Certified Hyperbaric Technologist Test certification validates expertise recognized by employers nationwide | Must complete continuing education to maintain active certification |
| Opens doors to advanced positions and leadership roles | Pass rates vary — thorough preparation is essential for success |
| Demonstrates commitment to professional standards and ethics | Some certifications require prerequisite experience or education |
Try these questions from our free Certified Hyperbaric Technologist Test practice tests. The correct answer and an explanation follow each question.
What pre-treatment checks must a hyperbaric technologist perform before each treatment?
Answer: A. Chamber integrity inspection, life support systems verification, fire suppression readiness, and communication systems test
Pre-treatment checks include chamber structural inspection, oxygen and air supply verification, BIBS function testing, fire suppression system check, communication system verification, emergency decompression readiness, and life support equipment calibration.
The role of the Hyperbaric Technologist during a monoplace chamber treatment primarily includes:
Answer: A. Monitoring patient condition, managing chamber pressure and gas supply, and responding to emergencies
The technologist manages all operational aspects of the treatment — pressure, gas supply, patient monitoring — from outside the chamber.
During a hyperbaric treatment the chamber loses external power. The technologist should be prepared to:
Answer: B. Switch to backup/manual control and continue a controlled treatment or decompression
Chambers have manual backup controls so a controlled decompression can continue safely during a power failure.
The UHMS-approved indications list is important for hyperbaric facilities because:
Answer: A. It defines reimbursable diagnoses and guides clinical decision-making for appropriate HBO use
The UHMS indication list is used by CMS and insurers for reimbursement eligibility and guides clinicians on evidence-based use of HBO.
Take the full Certified Hyperbaric Technologist Test practice test
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