The HNP Series needle hydrophones are excellent sensors for laboratory use in ultrasonic field mapping, with pinpoint access and good spatial resolution. While they have lower sensitivity than the HNC series, these hydrophones have a flatter response and better directivity.

	HNP-0200	HNP-0400
Frequency range (±6dB)	1 to 20 MHz
* EOC Nominal Sensitivity [dB re 1V/μPa]	-278	-266
* EOC Nominal Sensitivity [nV/Pa]	13	50
Acceptance angle (-6dB at 5 MHz)	110°	60°
Capacitance	70 pF
Max. Operating Temperature	50°C

* EOC ("end of cable") is the open-circuit output sensitivity of the hydrophone. Calibration with an amplifier can be determined from the gain and input impedance of the amplifier.