Checking The Calibration - Datex-Ohmeda Tec 7 User's Reference Manual

Checking the calibration

1175-0013-000
The accuracy of the measuring equipment must be considered when
obtaining the readings!
Sevoflurane Dial Setting
1%
3%
5%
Enflurane, Halothane or
Isoflurane Dial Setting
1%
3%
5%
The performance of most vaporizers that are in clinical use can be confirmed by observing
patient signs and consumption of anesthetic agents. Some users may, however, wish to
employ analyzers either as a routine procedure or as part of an investigation to determine
whether any abnormalities of performance have developed.
To help to achieve the reliability and consistency of performance of the Tec 7 Vaporizer,
Datex-Ohmeda uses closely specified test conditions, test methods and detailed protocol
in conjunction with training, experience and quality auditing systems. For these reasons,
the full program necessary to help to ensure that a vaporizer complies with Datex-Ohmeda
specifications cannot practicably be carried out in a field situation.
The following points must be considered when any measurements are being carried out on
vaporizers to assist in determining whether any abnormalities of performance have
developed.
1. To predict the concentration that the vaporizer can be expected to deliver, the
detailed nominal performance data and the preceding comments must be taken
into account.
2. The method of test used must not be such that it bears little relation to normal
conditions of clinical use.
3. Any sampling techniques used must be such as to ensure the following:
a. The sample is fully representative of the vaporizer output, which may not be a
homogeneous mixture at the vaporizer outlet.
b. The absorption of agent by any connecting tubing is negligible.
4. If a number of vaporizers are being examined at the same time the probability of all
of them being consistently in error is so remote as to be negligible and the cause of
any apparent error probably lies in the test method employed.
5. Consistent and reproducible analytical techniques must be used.
6. If unexpected results are obtained, it is a wise precaution to repeat the observation
because the vaporizer may be more reliable than the techniques used to observe its
performance.
Min Vol% Max Vol%
.6 1.40
2.55 3.45
4.25 5.75
Min Vol% Max Vol%
.75 1.25
2.55 3.45
4.25 5.75
5 Maintenance
5-3