Formerly Moduflex Anesthesia Equipment, Inc.   

Vaporizer Calibration Services

 Vaporizer calibration services


Effective December 2013, US Veterinary Equipment Inc., after 10 years in business,  added Anesthetic vaporizer processing to it's list of products and services. After moving to a larger and more modern facility, we dedicated 25% of our new space to vaporizer calibration services.


We have built, and equipped a new temperature and humidity controlled clean room, acquired testing monitors, ultrasonic cleaning equipment, pressure testing stations,  ducted exhaust hoods, oxygen generation equipment, waste gas system, compressors, and of course our own inventory of anesthetic vaporizers.


We can calibrate your TEC3, TEC4, TEC5, Ohio 100, Drager 19.1 and Penlon vaporizers



We can calibrate and return your vaporizer from our facilities, just ship us your vaporizer for calibration and we will be pleased to calibrate the unit for you,


Use our service exchange service where we will ship you an identical vaporizer, have yours picked up, you then keep ours and send us your used unit which we will process and eventually send to another client.


Keep in mind that Vaporizer calibration is only part of your required Anesthesia machine service. Calibrating a vaporizer may not solve all your machine problems. We recommend annual anesthesia machine service. Vaporizer calibration should be performed every 1,3, or 5 years depending on Agent. and/or application.


The anesthesia vaporizer is a critical component of your veterinary anesthetic machine. It is very important to ensure that the appropriate percentage of anesthetic agent is being delivered. A malfunctioning vaporizer can be the cause of inappropriate depth of anesthesia (ex: animals under too lightly or too deep) and may also be the reason you “lose” a patient.

Most vaporizers used today in veterinary practices are used with either Isoflurane or Sevoflurane. There are still some Halothane (fluothane) vaporizers on the market, however, the agent is hard to come buy as most manufacturers have discontinued its production.


Frequency of service


You should have your veterinary anesthesia machine maintained annually. Leaks on your machine can provoke dilution of anesthetic gasses and pollute your environment, not to mention increase your operating costs. “The fact that you have no problems keeping your animals under does not mean that your staff is not breathing the gasses all day long as well”. At the time of service the technician should have an anesthetic agent monitor and should provide you with the readings of the vaporizer. It is important to note that these readings are only an indication of the vaporizer output at the time of inspection, it is not a calibration. Calibration of vaporizers is impossible to perform “on-site” as it must be done in a controlled environment. Anyone who tells you otherwise is misleading you.

Most vaporizers on the market are considered “in spec.” if the output is within +- 15% of the dial setting. If the output is beyond that the technician will recommend exchanging your vaporizer with a freshly calibrated one or to send your vaporizer out for recalibration.


Why can vaporizers not be serviced on-site?

Vaporizer output is affected by the temperature of the agent. The colder the agent, the lower the vaporizer output; the hotter it gets the higher the output. Several factors affect the temperature. The oxygen flow through the anesthesia vaporizer cools the agent down; the room temperature affects the vaporizer temperature. The vaporizer contains a thermostat which regulates the output to compensate for these temperature variations but it has its limits. 


In order to recalibrate the thermostat it must be done in a temperature controlled environment.


Adjustments are made at precise temperatures and rechecked with a minimum pause of 4 hours between adjustments to confirm stability. Several subsequent identical readings are required before considering the calibration to be valid. This process may take up to 5 days. Once completed, the vaporizers are fully dried before shipping.


Isoflurane & Sevoflurane

Since these agents do not contain Thymol, they do not leave deposits in the vaporizer and need less frequent recalibrations. It is still necessary to have the output checked annually when verifying your anesthesia machine. An indication that your vaporizer is due for recalibration is if you find yourself routinely having to use concentrations higher or lower than you generally use. Naturally, it is assumed that you perform daily leak checks on your anesthesia machine.

Replacement parts

During the recalibration process, many parts may require replacement. The wick assemblies, the o-rings, etc., should always be replaced. Any other worn part should also be replaced.

Transport preparation

Before sending your vaporizer for recalibration it must be drained of all agents. Leaving agent in the vaporizer can cause damage. Proper packaging is very important.

First use

When you fill your vaporizer for the first time it may seem that you are losing agent rapidly. This is normal. A cotton wick inside the vaporizer absorbs a great deal of liquid and requires 2 to 3 fillings before being fully saturated.