Checking The Calibration - Ohmeda Tec 3 Bedienungsanleitung

Checking t h e Calibration
General
The cUnical adequacy and reUabiUty of Ohmeda Tec
Vaporizers have been demonstrated by the most stringent
proof of aU - that of continued widespread satisfactory use
throughout the world over many yeeirs involving hundreds
of miUions of successful administrations.
The performance of most Tec Vaporizers which are in
cUnical use is monitored by observing patient signs and
consumption of anaesthetic agents. Some users may,
however, wish to employ analysers to determine whether
any abnormaUties of performance have developed either as
a routine procedure or as part of an investigation.
In order to achieve the reUeibiUty and consistency standards
of Tec Vaporizers, Ohmeda use closely specified test
conditions, test methods and detailed protocol in
conjunction with training, experience and quaUty auditing
systems. Because of this the fuU progamme necessary to
ensure that a vaporizer compUes with Ohmeda standards
cannot be practicably carried out in a field situation.
The foUowing points should be considered when any
measurements are being carried out on vaporizers to
determine whether any abnormaUties of performance have
developed.
1) In order to predict the concentration the vaporizer
can be expected to deUver the detailed nominal
performance data, and the preceding comments
should be taken into account.
2) The method of test used should not be such that it
bears Uttle relation to normal conditions of cUnical use.
3) Any sampUng techniques should be such as to
ensure:
The sample is fuUy representative of the vaporizer
output, which may not be a homogeneous mixture at
the vaporizer outlet.
Absorption of agent by any connecting tubing is
negUgible.
4) If a number of vaporizers are being examined at the
same time the probabiUty of them aU being
consistently in error is so remote as to be negUgible
and the cause of any apparent error wiU Ue in the test
method employed.
5) Consistent and reproducible analytical techniques
should be used.
6) If unexpected results are obtained it is a wise
precaution to repeat the observations since the
vaporizer may be more reUable than the techniques
used to observe its performance.
7) If unexpected results occur it is also worthwhile
checking for sources of error (e.g flowmeter, leaks,
absorption by adjacent components etc.)
8) FuU account should be taken of any extraneous
effects on the analyser which may arise from changes
in carrier gas composition.
9) If the anaesthetic machine on which the vaporizer is
fitted is left for a period of time with no gases
flowing, sensitive analysers may detect smaU
concentrations of agent for a short time at the machine
outlet after the gsis flow is tumed 'on' with the
vaporizer tumed 'off. This concentration can be
expected to faU rapidly to zero (e.g. v^rithin about 15
seconds at 5 Utre/min.). This phenomenon is a normal
characteristic of anaesthetic vaporizers and
anaesthetic machines.