I.S. EN 61266:1997

FOREWORD
INTRODUCTION
1 Scope
2 Normative references
3 Definitions
4 List of symbols
5 Configuration
6 Performance
   6.1 Acoustic working frequency
7 Safety
8 Tests
   8.1 Acoustic working frequency
   8.2 Output power
   8.3 Spatial-peak temporal-peak acoustic pressure
   8.4 Effective area of the ultrasonic transducer active element
   8.5 Overall sensitivity
9 Preferred method for reporting performance of existing
   equipment
10 Specifications for labelling
11 Sampling
Annexes
A (informative) Choice of target and determination of target
                 plane-wave reflection loss
B (informative) Typical test equipment and test procedures
C (informative) Determination of the two-way insertion loss of
                 acoustic attenuators
D (informative) Rationale
E (informative) Bibliography
ZA (normative) Normative references to international
                 publications with their corresponding
                 European publications

Applies to ultrasonic Doppler foetal heartbeat detectors which generate a single ultrasound beam and consist of a hand-held probe which is applied to the maternal abdomen to obtain information on foetal heart activity by means of the Doppler method using continuous wave (c.w.) or quasi-continuous wave ultrasound.