Lion alcolmeter S-D2 breath alcohol tester Instruction Manual

lion alcolmeter S-D2

®

Instruction Manual

Please read this manual carefully

BEFORE using the instrument for the first time

This is an abbreviated version of the Handbook, intended for electronic transmission.

Medical Applications

Instruments in the lion alcolmeter

®

range enable medical personnel to carry out on-the-spot determinations of a patient’s breath alcohol level. The instruments (S-D2 and 500 only) may be used on conscious or unconscious patients, the overall test procedure taking only one minute to complete. lion alcolmeter

®

instruments are, in particular, relevant to use in the following areas:

•

•

•

•

Accident & Emergency

Alcohol Detoxification

Urology

Research

Lion Laboratories Ltd. Ty Verlon Industrial Estate, Barry, Vale of Glamorgan CF63 2BE, U.K.

Tel: +44 (0)1446-724500 Fax: +44 (0)1446-724501 E-mail: [email protected]

Web: http://www.lionlaboratories.com

© 2009, Lion Laboratories Ltd.

Section 1 – Principle of Operation

The lion alcolmeter S-D2

®

is designed to sample breath from deep in the lungs; this deep-lung air has been in close contact with the blood and so gives the truest reflection of the amount of alcohol in the subject’s body. The instrument is simple to operate and may be used as often as required, provided that a suitable delay is allowed between tests. This time delay allows the fuel cell to clear itself of alcohol from a breath sample and so prevent the possibility of additive readings. Unless the breath alcohol level of a breath sample is very high, the instrument will generally be clear enough to receive and analyse the second sample in less than 2 minutes.

The Fuel Cell Sensor

The instrument uses an electrochemical fuel cell to detect and measure the concentration of alcohol vapour in expired breath. When breath containing alcohol is drawn into the fuel cell by means of the sampling system, a small voltage is generated in proportion to its breath alcohol concentration. This voltage is fed to an electronic amplifier and displayed on a digital meter.

The Sampling Lights A and B

The instrument incorporates two breath sampling lights, controlled by an interlinked pressure switch and timer system; these are designed to indicate to the operator when deep-lung breath is being blown through the mouthpiece. By blowing at a certain pressure that is strong enough to bring on light A and continuing to blow at that pressure, air from the top of the lungs is “discarded” so that when light B comes on, deep-lung breath is being blown through the mouthpiece.

The Sampling System

Below the SET button of the sampling system is a diaphragm; when the SET button is pressed down, it is held in place by a spring-loaded catch. When the READ button is pressed at the moment sampling light B illuminates, the SET button is released pulling up the diaphragm and so drawing a small amount of breath from the mouthpiece into the fuel cell sensor.

Section 2 – General Information

The lion alcolmeter S-D2

®

measures the concentration of alcohol in expired breath and is supplied as standard to display the result in mg/l BrAC(milligrams per litre Breath Alcohol

Concentration), with the readings rising in single-digit increments. However, it is also possible to display the result in terms of the equivalent Blood Alcohol Concentration (BAC). To do this, it is necessary to make use of a blood:breath ratio which varies from country to country. For example, in the UK, the blood:breath ratio is taken as 2300:1; in Germany it is 2100:1; in Norway it is 2000:1. If the instrument is to read in BAC units, this must be advised at the time of ordering.

When supplied reading in BAC, the readings rise in 5-digit increments.

The lion alcolmeter S-D2

®

has been designed primarily for use in the 10-40°C temperature range.

Although there is only a little loss in accuracy between 0-10°C, it is recommended that in very cold weather, the instrument is stored in a coat pocket (preferably inside coat) close to body temperature, until required.

If a breath sample is analysed soon after the subject has consumed a drink containing alcohol, the reading would be very high because of residual alcohol remaining in the mouth, so it is important to allow a period of about 20 minutes to elapse before taking a breath sample. This delay allows for any mouth alcohol to be dispersed.

Do not allow the subject to eat or drink before a breath test; certain cough sweets may contain alcohol.

Smoking just prior to a breath test will not influence the result, but do not allow tobacco smoke to be blown through the mouthpiece – this could damage the fuel cell.

Unless your instrument has been RFI–screened, ensure that no radio transmitter is currently being used in the immediate vicinity of the test.

For some applications (e.g. medical), it may not be essential that the A and B lights illuminate.

The operator is trying to ensure that the sample of breath to be analysed is from deep in the lungs to give the most accurate reflection of the amount of alcohol in the blood. As long as the subject is nearing the end of expiration and still blowing when the READ button is pressed, deep-lung air will still be sampled.

Section 3 – Instrument Features

SET button

This forms part of the sampling system. When fully depressed, the button locks to “SET” the instrument ready to take a breath sample. When the SET button rises, the sample to be analysed is drawn directly into the fuel cell sensor.

READ button

This forms part of the sampling system, and has 2 functions:

1. To release the SET button, so taking the sample

2. Switching on the amplifier and display systems

The READ button is spring-loaded. Pressing it briefly will perform function 1 above; constant pressure is required for function 2.

Alcohol Level Display

3-digit, liquid crystal display shows the breath alcohol concentration of the subject (in single digits mg/l BrAC as standard). The display has built-in illumination and is activated by depressing the

READ button. If the left-hand character shows L when the READ button is depressed, then the battery should be replaced.

Breath Sampling Lights

Light A illuminates to indicate that the subject is blowing hard enough. Light B illuminates when the subject has blown for long enough, to indicate that the READ button should be pressed – i.e. when the subject is providing a suitable sample of breath for analysis.

Sampling Port

This forms the entrance to the fuel cell sensor. When inserted into the small hole in the side of the mouthpiece, it allows a small portion of breath to be drawn into the instrument for analysis.

Mouthpiece

This is attached to the sampling port. For reasons of hygiene, mouthpieces are individually wrapped and are disposable. A new mouthpiece must be used for each individual breath test.

When unwrapped, mouthpieces should only be handled by the exhaust end to avoid contamination or transference of saliva.

Battery

Is located behind the sliding base. It should be replaced when L appears on the left of the display.

Calibration control

This screw control on the right-hand side of the case is used for periodic calibration adjustments.

Section 4 – Subject Breath Test

Preliminary

Refer to section 2 with regard to:

Temperature

Mouth Alcohol

Eating or Drinking

Smoking

RFI

Ready Check

The instrument should now be checked to ensure it is ready to receive a breath sample. This checks that the fuel cell sensor is free of alcohol from a previous sample. Elimination of alcohol from the fuel cell will take a couple of minutes (longer in exceptional cases) depending on how much alcohol was present in the last breath sample.

Ensure the SET button is locked down, depress the READ button and hold down for at least 10 seconds. This will release the SET button and switch on the amplifier and display circuits; observe the display. The reading should not exceed 002 after 10 seconds (if the readings on the display rise in single increments) or 005 (if the readings on the display rise in increments of 5).

If the display shows higher than these readings during the Ready Check, it may be that the fuel cell still has residual traces of alcohol from a previous breath sample. In this case, depress the

SET button to lock and wait a further minute before repeating the Ready Check.

If the left-hand digit shows as L, replace the battery.

Set

Assuming the Ready Check was satisfactory, the sampling system must now be set so that it is ready to draw a breath sample into the fuel cell for analysis. Press down the SET button until it locks.

Attach mouthpiece

Remove the mouthpiece wrapper from the exhaust end, leaving the wide-bore, lipped end in the wrapper so that the operator is not touching the part of the mouthpiece that the subject will blow through. Attach the mouthpiece to the sampling port on the top of the instrument, and then slide the wrapper from the wide-bore, lipped end. This sampling port forms the entrance to the fuel cell and pressure switch and it is essential that the mouthpiece is pushed fully home onto it. The subject must be offered the wide-bore, lipped end of the mouthpiece to blow through.

The instrument is now ready to receive a breath sample for analysis.

Instruct the Subject

Tell the subject exactly what he must do to provide a suitable sample of breath for analysis. Tell him he must fill his lungs, blow strongly enough to bring on light A and keep blowing at that pressure long enough to bring on light B. He must then continue blowing until he is told to stop, i.e. after you have pressed the READ button to draw a sample of breath from the mouthpiece into the fuel cell.

Warn the subject that if he fails to bring on both sampling lights, he will have failed to provide a suitable sample of breath for analysis, which may be an offence.

If he blows too hard, he may run out of breath before the B light comes on; just a moderate breath flow is required.

The subject should also keep his hands down, away from the instrument.

Take sample

The subject now fills his lungs and blows through the wide-bore, lipped end of the mouthpiece.

He must blow strongly enough to bring on light A and continue to blow at this pressure long enough to bring on light B. At this stage, he will have expelled his top-lung air, so that deep-lung air is now being blown through the mouthpiece; this deep-lung air gives the truest reflection of the amount of alcohol in the blood.

When the B light comes on, press and hold down the READ button; this releases the SET button, which pulls up the diaphragm and draws a small portion of breath from the mouthpiece directly into the fuel cell sensor.

The subject should still be blowing when the sample is taken, i.e. both lights A and B must be on, and so he must keep blowing until he is told to stop. If he stops blowing prematurely, the sampling lights will go out.

Observe Display

Withdraw the instrument from the subject and continue to hold down the READ button. The fuel cell now develops its signal, which takes 30 – 40 seconds to complete from the time of sampling.

The maximum signal is a measure of the amount of alcohol in the breath sample.

As the fuel cell charges up, it will cause the display reading to rise; the final value, after 30-40 seconds, is the subject’s alcohol concentration.

If the READ button is accidentally released during the reading development time, the fuel cell signal will be unaffected, provided the SET button is not depressed. Just re-press the READ button within the 30-40 seconds reading development time to continue reading the alcohol level on the digital display.

Discard mouthpiece

Now remove and discard the mouthpiece. On no account use the same mouthpiece for subsequent tests on either the same or different subjects.

Reset and Wait

The instrument must now be reset so that it is ready for re-use. Depress the SET button until it locks, which “flushes out” the fuel cell and short-circuits its electrodes, so speeding up returning the voltage to zero.

Section 5 – Calibration Checking and Adjustment and the AlcoCal

®

standard

The sensitivity of fuel cell to alcohol vapour changes slowly with time. Therefore, to ensure continued optimum instrument operation, it is necessary to check its accuracy at regular intervals, and to carry out an appropriate adjustment when necessary.

It is for the user organisation to decide how often the accuracy is checked, but it is recommended that a calibration check is carried out at least once per month. Calibration adjustment is only required when the reading obtained from the calibration check is unacceptable to the organisation; for example greater than 5% or 10% away from the value of the standard so used.

In addition, a calibration check can also be carried whenever it is necessary to verify the accuracy of a breath test reading.

AlcoCal

®

Alcohol Standards

The calibration check and adjustment processes are most conveniently carried out using the

AlcoCal

®

alcohol vapour standard. This is a mixture of alcohol vapour in air at a known concentration, contained in a pressurised cylinder.

Provided it is within certain limits, the actual value of the standard is not critical, but it must of course be known.

NOTE: a wet bath simulator may also be used for either process: please contact Lion for relevant information, if required.

Two types of AlcoCal

®

standard are available:

•

AlcoCal

®

-M: this disposable cylinder has a six-month shelf life and contains sufficient vapour

• for approximately 50 samples. The alcohol concentration value is stated to within +/- 10% of the true value.

AlcoCal

®

-2AL: a high-pressure disposable cylinder fitted with a re-useable regulator. It contains sufficient vapour for approximately 300 samples, and is supplied with Connector

Tubes for attachment to a mouthpiece as used with the S-D2. The stated alcohol concentration is within +/- 3%, and is valid for approximately thirty-four months.

Units of Alcohol Measurement

The alcohol level in AlcoCal

®

standards is normally given in units of mg/l BrAC (ie milligrams per litre Breath Alcohol Concentration). But if the lion alcolmeter S-D2

® of measurement, the AlcoCal

® supplied with an Explanatory Booklet giving information on how to convert the mg/l BrAC value of the AlcoCal

®

is reading in some other unit

standard will still be suitable for use, since each such standard is

to the units actually used by the instrument.

AlcoCal

®

Standards and Atmospheric Pressure Effects

The level of alcohol in a subject’s breath is completely unaffected by changes in atmospheric pressure; the information below applies only to the alcohol concentration in the AlcoCal

®

standard.

The stated alcohol value of each AlcoCal

®

standard applies only when the cylinder is used at sea level at normal atmospheric pressure (1 bar). At lower atmospheric pressures the alcohol vapour concentration will be lower; but it will be higher at atmospheric pressures greater than standard.

This change in alcohol concentration due to normal atmospheric pressure changes at sea level is generally so small as to be negligible, but if the AlcoCal

®

is used at high altitude, significant error would be produced if a correction was not made. Finally, if the atmospheric pressure even at sea

level is very low [such as during a tropical storm], or is very high, then must also be taken into account when using an AlcoCal

®

.

Barometric Pressure Correction Look-up Table for AlcoCal

®

Atmospheric

Pressure mB

650

700

750

800

850

900

950

1000

1010

1050

AlcoCal

®

Value

mg/l BrAC

0.22

0.24

0.26

0.28

0.29

0.31

0.33

0.34

0.35

0.36

Example:

A 0.35mg/l AlcoCal

®

is to be used where the atmospheric pressure is only 950mB. Standard atmospheric pressure at sea-level is 1,013mB, so the BrAC value of the standard now becomes:

950 x 0.35 = 0.32mg/l BrAC

1,013

(rounded down)

But if the atmospheric pressure was higher than standard, say 1050mB, then the value of the same AlcoCal

®

would be:

1,050 x 0.35 = 0.36mg/l BrAC (rounded down)

1,013

AlcoCal

®

Standards and Atmospheric Temperature Effects

Large ambient temperature changes will also modify the alcohol level in the vapour leaving an

AlcoCal

®

standard. They should therefore be kept away from excess heat and cold, and if they are exposed to such temperatures, should be allowed to recover. Ideally, an AlcoCal

®

standard should not be used if it is outside the temperature range 15 – 30°C.

Calibration Checking

®

and the S-D2 are at room This procedure must be carried out when both the AlcoCal temperature in the range 15 – 30°C. To ensure that the fuel cell is at its optimum sensitivity, the

S-D2 should not have analysed any sample containing alcohol in the previous 10 minutes.

Prepare the AlcoCal

®

Standard

Note the value of the AlcoCal

®

to be used (making allowance for atmospheric pressure and units of measurement, as previously described). Now fit the Dispensing Top to the AlcoCal

Connector Tube to the regulator of the AlcoCal

®

-2AL. If the AlcoCal

®

-M, or the

®

-2AL has not been used within the previous two hours, press and hold down the push-button for about five seconds to flush out of the regulator of any stale and depleted alcohol vapour.

Ready Check

Ensure the SET button is locked down, depress the READ button and hold down for at least 10 seconds. This will release the SET button and switch on the amplifier and display circuits; observe the display. The reading should not exceed 002 after 10 seconds (if the readings on the display rise in single increments) or 000 (if the readings on the display rise in increments of 5).

If the display shows higher than these readings during the Ready Check, it may be that the fuel cell still has residual traces of alcohol from a previous breath sample. In this case, depress the

SET button to lock and wait a further minute before repeating the Ready Check.

If the left-hand digit shows as L, replace the battery.

Set

Assuming the Ready Check was satisfactory, the sampling system must now be set so that it is ready to draw a sample of the AlcoCal

®

SET button until it locks.

standard into the fuel cell for analysis. Press down the

Sample the AlcoCal

®

standard

Fit a new pressure mouthpiece to the S-D2, then push this over the Dispensing Top on the

AlcoCal

®

-M or the Connector Tube on the AlcoCal

Dispensing Top (AlcoCal

®

®

-2AL to form an airtight fit. Push down the

-M) or push-button (AlcoCal

®

-2AL) and allow vapour to flow for at least

6 seconds. After about 5 seconds, but with vapour still flowing, press the READ button to take a sample of the vapour into the instrument. Now release the cylinder control to stop gas flow.

Method of Use of an Alcohol Standard

1. Attach the mouthpiece to dispensing top

(AC-M) or to connector tube (AC-2AL).

2. Fully depress and hold down dispensing top

(AC-M) or push button (AC-2AL).

3. After 5 seconds of gas flow press the

‘READ’ button

4. Release dispensing top/push button and detach instrument.

Observe the display

Disconnect the instrument from the mouthpiece, continue to hold down the READ button and observe the display. The value should rise and finally stop some 30 – 40 seconds from sampling.

If the maximum value shows an unacceptable deviation from the AlcoCal

® adjustment is required.

value, then calibration

Reset and Wait

Depress the SET button to lock and allow the fuel cell to clear itself of alcohol.

Calibration Adjustment

Turning the control clockwise DECREASES the reading on the alcohol level display in response to sampling the standard.

This procedure must be carried out when both the AlcoCal

®

and the S-D2 are at room temperature in the range 15 – 30°C. To ensure that the fuel cell is at its optimum sensitivity, the

S-D2 should not have analysed any sample containing alcohol in the previous hour.

The calibration control

Adjustment is carried out using the small screw adjustment located on the right-hand side of the instrument, accessed through a hole in the instrument case.

Ensure that the small screwdriver supplied with the instrument is to hand.

Prepare the AlcoCal

®

Standard

Note the value of the AlcoCal

®

to be used (making allowance for atmospheric pressure and units of measurement, as previously described). Now fit the Dispensing Top to the AlcoCal

®

-M, or the

Connector Tube to the regulator of the AlcoCal

®

-2AL. If the AlcoCal within the previous two hours, press and hold down the push-button for about five seconds to flush out of the regulator of any stale and depleted alcohol vapour.

®

-2AL has not been used

Ready Check

Ensure the SET button is locked down, depress the READ button and hold down for at least 10 seconds. This will release the SET button and switch on the amplifier and display circuits; observe the display. The reading should not exceed 002 after 10 seconds (if the readings on the display rise in single increments) or 000 (if the readings on the display rise in increments of 5).

If the display shows higher than these readings during the Ready Check, it may be that the fuel cell still has residual traces of alcohol from a previous sample. In this case, depress the SET button to lock and wait a further minute before repeating the Ready Check.

Set

Assuming the Ready Check was satisfactory, the sampling system must now be set so that it is

standard into the fuel cell for analysis. Press down the ready to draw a sample of the AlcoCal

®

SET button until it locks.

Sample the AlcoCal

®

standard

Fit a new pressure mouthpiece to the S-D2, then push this over the Dispensing Top on the

AlcoCal

®

-M or the Connector Tube on the AlcoCal

Dispensing Top (AlcoCal

®

-2AL to form an airtight fit. Push down the

®

-M) or push-button (AlcoCal

Adjust the display to the value of the AlcoCal

®

®

-2AL) and allow vapour to flow for at least

6 seconds. After about 5 seconds, but with vapour still flowing, press the READ button to take a sample of the vapour into the instrument. Now release the cylinder control to stop gas flow.

Keep holding down the READ button and with the screwdriver provided, quickly turn the calibration control ANTI-CLOCKWISE so that after about 10 seconds, the display reading is higher than the value of the AlcoCal

®

. As the fuel cell charges up and the display rises further, turn the control CLOCKWISE to decrease the reading on the display to match the value of the

AlcoCal

®

. If this is done quickly, the reading on the display will continue to rise so turn the control

CLOCKWISE again to decrease the reading on the display to match the value of the AlcoCal

As the fuel cell reaches its peak voltage so that the display reading remains the same as the

®

.

, the control will require no further adjustment – the instrument is calibrated. value of the AlcoCal

®

Do not turn the control to increase the reading once the display (fuel cell voltage) has passed its peak reading.

Note: if the display reading cannot be brought up to the AlcoCal

®

value, the fuel cell is at the end of its life and must be replaced.

1. Carry out ‘READY CHECK’, then ‘SET’ the instrument. 2. Sample the AlcoCal

®

standard.

3. Adjust the display to slightly exceed the AlcoCal

®

value. 4. Turn the control slowly back to hold the display at the

AlcoCal

®

value.

Reset and Wait

Depress the SET button to lock and allow the fuel cell to clear itself of alcohol.

Calibration Checking

After leaving the instrument for 10 minutes with the SET button locked down, repeat the calibration checking procedure as described earlier. If calibration adjustment has been correctly carried out, the calibration check will confirm this.

Section 6 – Routine service checks

These additional checks that can be carried out monthly will ensure that other aspects of the lion alcolmeter S-D2

®

are in proper working order.

Battery check and replacement

If the left-hand display character shows L when the READ button is depressed, then the battery is low in voltage and needs to be replaced before the instrument is used again. At the base of the instrument, slide the battery cover to one side, and gently disconnect the battery. Ensure that the replacement battery is fitted to the correct contacts and fitted inside the battery compartment.

Sampling system check

This check will ensure that the sampling system is not leaking or blocked.

Press the SET button to lock down and place a forefinger tightly over the sampling port, so as to form an airtight seal. Press the READ button fully down and watch the SET button – this should not rise since the sampling port is blocked, so air cannot be drawn into the sampling system. If the SET button does rise, then there is probably a leak in the system – consult a qualified technician.

Remove the forefinger from the sampling port and the SET button should immediately rise; if it rises only slowly, the sampling system may be blocked – again, consult a qualified technician.

DO NOT COVER THE SAMPLING PORT AND

THEN FORCE THE SET BUTTON DOWN.

THIS WOULD RUPTURE THE SAMPLING

DIAPHRAGM OR FUEL CELL ELECTRODES.

Sampling Lights check

This procedure checks the operation of the breath pressure switch, and the timing and operation of the breath sampling lights.

Ensure the SET button is locked down. Place a forefinger over the sampling port and apply continuous pressure to the SET button. This should activate the pressure switch so causing sampling light A to illuminate, followed about 2.5 seconds later by light B. If there is a problem consult a qualified technician.

Test Fuel Cell reset switch

When a sample containing alcohol has been taken, the reading is cleared from the display and fuel cell recovery accelerated by depressing the SET button. This short-circuits the fuel cell electrodes and so accelerates its discharge.

To test that this short-circuiting switch is working, take a sample of AlcoCal

®

into the instrument.

Hold down the READ button and observe the display as it starts to increase up to the value on the AlcoCal

®

label; then, still holding down the READ button, press the SET button fully down (i.e. both buttons down together) – this should cause the display to reset to 000. If not, consult a qualified technician.

Fuel cell replacement

When the fuel cell has reached the end of its working life as judged by the inability to correctly adjust calibration of the instrument, the complete instrument has to be returned to the manufacturer or local distributor for a replacement fuel cell to be fitted.

Section 7 – Use of the instrument in medicine

As well as use by law enforcement and industrial safety authorities, the instruments in the lion alcolmeter

®

range are commonly used in medicine, particularly in the following areas:

Accident & Emergency

Particularly in the diagnosis of coma and the monitoring and treatment of patients with head injuries.

Alcoholism treatment

Routine tests on day patients or residents in alcohol detoxification units to ensure compliance with treatment programmes.

Gastroenterology

In the treatment of alcohol-related stomach disorders and as a means of measuring gastric emptying.

Pharmacology

Such as drug-related and other pharmacokinetic studies.

Fluid uptake

In resection surgery.

NOTES

•

Portable and mobile RF communications equipment can affect Medical Electrical Equipment.

•

The lion alcolmeter S-D2

®

is intended for use by healthcare professionals only. This equipment may cause radio interference or may disrupt the operation of nearby equipment. It may be necessary to relocate the instrument or shield the location.

•

The lion alcolmeter S-D2

®

should not be used adjacent to other equipment and if adjacent use is necessary, the instrument should be observed to verify normal operation.

•

When storing the instrument for long periods (greater than 1 month) the battery should be disconnected and removed.

Breath Sampling from Conscious patients

Follow the breath test procedure as detailed in Section 3. For medical applications, when taking the breath sample, it may not be essential that the A and B lights illuminate. The operator is trying to ensure that the sample of breath to be analysed is from deep in the lungs to give the most accurate reflection of the amount of alcohol in the blood. As long as the subject is nearing the end of expiration and still blowing when the READ button is pressed, deep-lung air will still be sampled.

Breath Sampling from Comatose patients

Although it is deep-lung air that should normally be analysed, nasal sampling from comatose patients also gives reliable measurements. This is because the low tidal volume and slow respiratory rate in such persons together allow for alcohol equilibrium between the breath and the upper nasal mucosa and saliva in the mouth.

Ready Check

Ensure the SET button is locked down, depress the READ button and hold down for at least 10 seconds. This will release the SET button and switch on the amplifier and display circuits; observe the display. The reading should not exceed 002 after 10 seconds (if the readings on the display rise in single increments) or 000 (if the readings on the display rise in increments of 5).

If the display shows higher than these readings during the Ready Check, it may be that the fuel cell still has residual traces of alcohol from a previous breath sample. In this case, depress the

SET button to lock and wait a further minute before repeating the Ready Check.

If the left-hand digit shows as L, replace the battery.

Set

Assuming the Ready Check was satisfactory, the sampling system must now be set so that it is ready to draw a breath sample into the fuel cell for analysis. Press down the SET button until it locks.

Attach nasal tube

Remove a nasal tube from its pack by pushing out from the back and attach firmly to the sampling port on the instrument.

Take sample

Push the tube into the patient’s nose (or mouth if there is nasal haemorrhage) and pinch closed the other nostril. Observe the patient’s respiration during several complete cycles and towards the end of an expiration, but not during inspiration or when expiration has terminated, press the

READ button and withdraw the instrument from the patient.

Observe Display

Withdraw the instrument from the subject and continue to hold down the READ button until the display reaches its maximum reading.

Remove Nasal tube

Remove and discard the nasal tube; on no account use again, on either the same or a different patient.

Reset and Wait

Depress the SET button until it locks, which “flushes out” the fuel cell and short-circuits its electrodes, so speeding up returning the voltage to zero.

NOTE: When sampling breath from a comatose patient, the sampling lights will not operate because of the low expiratory pressure and tidal volume. Also, care must be taken to ensure that fluid is not taken into the instrument, as this would permanently damage the fuel cell sensor.