KC Digital flow meter, with back-run stop (Non-resetting)
23.091 - Digital flow meter	Short description: For determining the amount of water passing through a plankton net. For vertical pull only. For a horizontal pull you can also use flow meter 23.090. Diameter of propeller/counter body: 70/32 mm, length 185 mm, 5-digit counter; easy installation by a triple point connection of the nosepiece. With back-run stop for vertical operation. Can be used for full oceanographic depth. (free flooding).
Rigging instructions: Installation of the digital flow meter is made by a triple point connection of the nose piece inside the net ring.
	Determination of the water volume passing through a plankton net The digital flow meter incorporates a three blade impeller coupled directly to a five-digit counter which records each revolution of the impeller. Please note that the counter cannot be reset to "0". Before operating the unit, you must note all figures. The number of revolutions is read by noting the difference in beginning and end readings.
General   Flow meter For vertical pull only.     Material   Rotor Polyamide, PA 6.6 Nylon rotor Nose cone POM Plastic Body POM plastic Gear shaft Armaloyed stainless steel main rotor and idler gear shaft     Dimensions   Overall length 19,0 cm Standard rotor diameter 7,5 cm     Other data   Depth rating Unlimited (Free flooding) Data read out Five ten-digit counter wheels reading 00000 to 99999. One count per rotor revolution Counter 99999 counts, equal approx. 16,2 nautical miles. The counter cannot be reset. If you need to reset the counter you must use 23.090. Mounting Universal bridle allowing 3 point connection Threshold 20 cm/sec Range 20 cm/sec to 8,0 meter/sec
The pitch of the impeller is 0,3 m per revolution, i.e., the number of revolutions multiplied by 0.3 makes the towing distance. For quantitative measurements the threshold flow velocity of the impeller should not be smaller than 0,5 m/sec. For comparison measurements flow velocities smaller than 0,5 m/sec are possible. Example 1:   The number of revolutions is 100, this means a towing distance of 30 metres. The opening area of the plankton net must be known or has to be calculated. The water volume passed through the plankton net is determined as follows: Indicated number of revolutions x 0,3 x net opening area (m²) x 1000 = water volume. Example 2: The plankton net has a diameter of 40 cm, i.e, the opening area is 0,125 m². If the number of revolutions associated with a tow is 266 (noted from the digital flow meter counter), the water volume passed through the plankton net is 266 x 0,3 x 0,125 x 1000 = 9975 litres = 9,975 m3   Rinse with freshwater after use.