Features of Ultrasound Doppler Fetal Monitor MSLJB15:

High sensitive ultrasound probe 
Detect the heart rates of 16th week fetus 
Record the fetal heart beat by computer

Specification of Ultrasound Doppler Fetal Monitor MSLJB15:

Ultrasound operating frequency: 3.0MHz (2.5MHz and 3MHz optional, deviation from nominal rated operating frequency is no more than (±5%).
Comprehensive sensitivity: At a distance of 200 mm from the probe surface; the comprehensive sensitivity is no less than 90 dB.
Display range: 50-210 bpm
Error: ±2 bpm
Ultrasound output power: <20mW
Recommended coupling agents:
Skin irritation: none
Total bacterial: <1000 units/g
Faecal coliforms, pseudomonas rhamnosus, staphylococcus aureus: none

Sound speed: 1520-1620 m/s
Acoustic impedance: 1.5-1.7x106 Pa.s/m
 Acoustic attenuation: <0.05 dB/(cm.MHz)
Viscosity: > 15Pa.s
PH value: 5.5-8
Peak Negative Sound Pressure (P-) : <0.1MPa
Output Beam Intensity (Iob): <10mW/cm²_
Spacial-peak temporal-average intensity (ISPTA): <100mW/cm²