Home»Technical Insights»Nitrous Gas Delivery Systems

Nitrous Gas Delivery Systems

posted in: Technical Insights

Nitrous Gas Delivery System

Nitrous gas delivery systems are equipment used for conscious sedation therapy.  It is a device that outputs a mixture of nitrous oxide and oxygen gas to the patient, which is control by the dental surgeon.  The Nitrous Gas Delivery Systems controls the concentration of nitrous that is delivered to the patient, and these units are commonly used at dental offices to sedate patients who have anxiety from dental procedures.

General Use

Nitrous gas delivery systems are available as an analog or a digital system.  The analog systems require the user to control the output flows of both nitrous and oxygen gases with a knob or handle.  The user must set the knob to the desired output concentration using the gauge on the knobs or by calculating the flow rates.  Some nitrous gas delivery units do not have a concentration display and require the user to mathematically calculate the concentration using a formula.  These units allow for a nitrous gas concentration between 0% – 70% but some analog units only allow for a maximum concentration output of 50% nitrous gas.  The digital units allow for the user to set the output flow using push buttons and a LED display of the concentration and will alarm if any of the gas tanks are near empty.  Both these units have a safety system that recognizes when either gas loses flow or a tank becomes empty, and automatically shuts off the Nitrous gas to prevent an over concentration.  The digital units will trigger an audible alarm if any of the tanks are low or, if the analog system is connected to a digital gas manifold system, it will alarm the main system.


Preventative Maintenance

Calibration of these units is very important because it verifies correct flow rates and concentration levels to allow for a safe sedation.  Over time, the output from these units can change and cause an unsafe sedation procedure.  If, at any time, the unit has a nitrous concentration above 70%, the unit is deemed unsafe and requires calibration since high amounts of nitrous gas is very unsafe to a patient and can cause many short and long term health complications.


At TRH services we have the training and tools to make sure that your nitrous gas delivery system is in top performance.  Our tools allow us to view the concentration percentage and make any calibration adjustments that are required.  As part of our regular preventative maintenance program we perform a full leak test on your system and we ensure that there are no gases leaking into the atmosphere.  A full system check also includes testing your alarm system to see if it meets manufacturers’ specifications.  Having your system tested for leaks will prevent any health concerns from long term exposure of gases and will also save you money from replacing your gas tanks prematurely.



We frequently receive calls from clients regarding nitrous gas delivery systems that are not functioning.  Customers feel that the output flow is too low or too high and believe something is not working on the unit. Before we can make any decisions on whether the unit is not functioning correctly, we have created a short troubleshooting guide to save you any repair costs.


Breathing bag deflates too fast

The important thing about delivering the sedative to your patient is that when the unit is connected to the patient they are getting the proper amount of gas flow. The gases from the nitrous gas delivery unit flow into a breathing bag where it will mix and flow out to the patient.  If the patient demands more gas flow than what is being yielded, it will take all the gas from the bag and cause it to collapse. The two main reasons why the bag will deflate too fast is that the scavenging suction level is too high or the output flow is too low.  If the scavenging suction is set to high it will be removing any of the gases before the patient has a chance to inhale them and will consume more than is produced. If the flow rates are too low, the patient will be inhaling more gas than is produced for them. The key to a successful sedation is balancing the nitrous gas delivery systems output with the patients breathing rate and volume and having the scavenging system set correctly.


Breathing bag does not inflate

This issue can be caused by having too much suction causing the air inside the breathing bag to be removed.  If your breathing system is well balanced the problem with the bag deflating could be caused by a bane output valve that could be stuck open.  If this bane output valve is stuck open the nitrous unit would require service.


Unit is noisy

If the unit is making strange noises when delivering the sedation, it is possible that the valves and o-rings need to be replaced.  The most common issue when your unit is making noise is that the re-breathing bag could have a small hole in it and this would require the bag to be replaced.


Requires higher concentration to sedate a patient

This could be based on the size of the patient you are sedating but we recommend the unit to be calibrated to insure the units output is accurate.


The TRH Value

The added valve of choosing TRH Services to complete your maintenance and repairs on your nitrous gas delivery system is that we will ensure that your device will be in great working condition for you and your patients for the next year and it will be fully certified.  At TRH Services our expertise can help educate you on your nitrous gas delivery system and make sure that your unit is at top performance. We can provide onsite service to your facility if you are located in South-Western Ontario (London, Toronto, Kitchener, Waterloo, Cambridge, Guelph, Hamilton, etc.).


Common Nitrous Gas Delivery Systems

Listed below is a short list of some common nitrous units that we work on a regular basses:


ManufacturerModel NumberManufacturerModel Number
Accutron Inc.Digital UltraOrmco CorporationN/A
Ultra PCParker Hannifin Corporation40151617
Belmed Inc.5000Digital MDM
Fraser Sweatman Inc.MDMDigital-MDM
N/APorter Instruments Co.02000
MDS Matrx945000112045-2
Digital MDM91500167
MDM DigitalC300
Modular Driven Technologies Corp. (MDT)70-3500-30MDM
Fraser MDMMXR-1
MDMRA Medical Services LtdMDM



Written By: Matthew Chominiec C.tech
Edited By: Tyler Hasenpflug CET

2 Responses

  1. Barb Scott

    We had an issue with our Matrx unit that allowed the Nitrous to be dispensed and no oxygen. The fail safe alarm did not go off.

    • Tyler Hasenpflug

      Hi Barb,
      In this case you should stop using the unit and have the unit fully tested and inspected to ensure that everything on this unit gets repaired. Currently we would consider the unit to be unsafe.