Benefits of a Replaceable Sensor Feature

What is a replaceable sensor?

All breathalyzers need to be calibrated after a pre-determined period or number of tests. One of the latest progress in design is the availablility of breathalyzers that has user replaceable sensor. Click here for the list of products with this feature. With this feature, you can conveniently replaceable the sensor when a calibration is due hence eliminating the need to calibrate the breathalyzer at a service centre.

There are three main components on a pre-calibrated sensor module

  1. Sensor. The Sensor is mounted on the module and is positioned in the path of the airflow of the sample.
  2. Memory unit. Calibration data will be stored in the memory unit when the module has been manufactured. When a new sensor module is inserted into the breathalyzer, the breathalyzer reads from the memory unit for the calibration data. Calibration data includes date of manufacture, the unique voltage output graph of the attached sensor, etc.
  3. Printed Circuit Board (PCB). The sensor and the memory unit are mounted on the PCB which has an interface to connect to the breathalyzer's PCB.

Cost of Maintenance

Using a breathalyzer that comes with a replaceable sensor saves you time and money.

Suppose we have an AL6000 (Sensor Replaceable) and a AL5500 (Non Sensor Replaceable). Calibration is recommended every 6 months or 500 tests.

AL6000 (Sensor Replaceable)
AL5500 (Non Sensor Replaceable)
Cost of Breathalyzer $74.99 $69.99
Cost of a Sensor Replacement $27.99  
Cost of Calibration
Cost after 1 sensor change/calibration $102.98 $139.99
Cost after 2 sensor change/calibration $130.97 $209.98


For breathalyzers without replaceable sensor

For the majority of breathalyzers in the market that comes without replaceable sensor, it is possible to calibrate it using a piece of equipment called the wet bath simulator ('simulator'). This simulator works by creating alcohol vapor of a pre-determined concentration at a specfic temperature of 34 degrees celcius. Most breathalyzers in the market use 0.050% and 0.100% as the standard to calibrate. The simulator is filled with 500ml of standard solution. When the simulator releases the vapor of each concentration, it is oxidised by a fuel cell sensor and a electrical voltage will be generated If the sensor is semiconductor based, the resistance of the semiconductor sensor will change. The breathalyzer records that information generates a new breath alcohol-voltage graph. This breathalyzer becomes calibrated.

Can i calibrate it myself then?

Yes but the cost of doing so is prohibitive. A set of brand new wet bath simulators will cost around $1,800 and you need precision equipment to produce diluted alcohol of 0.050% and 0.100% concentration. The slightest deviation will result in a badly calibrated breathalyzer. 

Lack of fuel cell breathalyzer with replaceable sensor feature

This is a common request from our customers. The biggest engineering obstable to design a breathalyzer with replaceable sensor feature is the difficulty of creating a pump small enough to be mounted on the sensor module. Therefore replaceable fuel cell sensors today are not found  on hand held breathalyzers. 

We have partnered with a research engineering company to miniaturise the pump to be small enough to be mounted on the breathalyzer. Our hand held unit will be manufactured under the brand name of AlcoTrack and should be available by 2012.

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