Table of Contents
King Probe
- Description: CSIRO-KING Liquid Water Content Probe
- Manafacturer: Particle Measureing Systems Inc.
- Model: KLWC-5
- Serial Number: SN-PMI-1058-0704-86 (Purchased fall 2008)
- Accuracy: +/- 15% LWC (See http://www.atd.ucar.edu/raf/Bulletins/B24/kingLwc.html)
- 200 um Drops: - 50% LWC (See Walter Strapp paper, “Measurements of the response of hot-wire LWC and TWC probes to large droplet clouds”)
Instrument Requirements
- Power: 28 VDC 10 Amps [Heaters] 28 VDC 70-120 Watts [Source: Paul LeHardy]
- Weigth: 1.8 Kg (4 lbs) [Total weight for control Unit, display and sensor] [Source: Paul LeHardy]
- Size: width - 6 inch. Height - 12 inch. Depth - 12 inch. [Control Unit] [Source: Davie Delene]
- Hot Wire Size: 1.92mm Measured October 20, 2010 [Source: Aaron Ness]
- Hot Wire Diameter Size: 1.92mm, Length - 47.30mm Measured August 25, 2011, new element changed out on June 1, 2011 [Source: Aaron Ness]
Calibrations
- Calibration plots from calibration done on December 30, 2010 from 4550 to 4880 seconds from midnight.
Problem
During April 8, 2011 flight the signal voltage was negative.
Cause
The wire on the A/D board was connected backwards for this flight.
Solution
The A/D wires were switched. The King probe was tested on the ground to valid that there is positive voltage when the probe is turn on. Labels were put King Probe A/D wires.
Problem
During L3COM flight on November 24, 2004 the King Probe wire broke.
Cause
Normal to sometimes break.
Solution
King Probe wire replace after the flight.
Problem
During the TAMDAR Turbulence flight on September 9, 2005 the King Probe wire broke.
Cause
Flight encounted some heavy rain and a little hail. This resulted in breaking the broken wire.
Solution
King Probe wire replace after the September 13 ferry flight to Fairbanks, Alaska. The King probe power was not turn on during the ferry flights.
Problem
King Probe voltage possibly high. Probe does not match water content measured by other probes.
Solution
Varied voltage on a fan blowing on the hot wire of the probe. Dave and Aaron measured the following on 10/25/11 on data file 2011_10_25_19_24_46: 28.0 vdc on fan read 0.940 on King display, and current mesured 2.56 amps. 23.0 vdc, 0.88 displayed, 2.48 amps. 20.0 vdc, 0.84 displayed, 2.42 amps. 15 vdc, 0.75, 2.29 amps. 10.0 vdc, 0.64, 2.11 amps. 5.0 vdc, 0.27 displayed, 1.43 amps. 0.0 vdc, 0.29, 1.47 amps. re-did 28.0 vdc, 0.96 displayed, 2.57 amps.
Problem
11/5/2011 Flight. Anti-ice not working.
Solution
11/8/2011. 5 amp fuse blown in the back of the display head in 3rd rack. Heater/Element issue. Resoldered spare heaters on a new element. Need to check out w/ freeze spray to confirm all fixed. Called Bill Dawson at DMT to order spare heaters. DMT still sells the elements and the heaters. I will get a quote on cost and log the part numbers. Heater P/N HTR-0134
Problem
December 30, 2021 (12/30/2021 - David Delene). Ground Test had approximately 0.08 volts on slave voltage.
Solution
12/31/2021. Replace the Sensor Wire with a new one. Across the middle pin (of the 5 pins) on the Sensor Wire should have almost zero resistance (conduction test, not open circuit). Tested all spare wires. Have three good wires remaining, 6 broken wires. All wires are stored in the King Probe Box. Will order thermal compound for King Probe Box to use on heaters, which we should store in the King Probe Box.
Problem
High Slave Voltage (01/14/2022 - David Delene). During the January 14, 2022 IMPACTS flight, the King Probe Slave voltage was above 6.0 volts all during the flight, when the voltage should be 5.0 volts.
Solution
01/14/2022. The slave negative connected on the analog to digital board was not secure on the screw connections. Put new pin ends on all slave and signal, positive and negative connectors. Installed the wires to the screw connectors making sure the wires don't move.
Problem
High Slave Voltages (01/17/2022 - Jennifer Moore). During the January 17, 2022 IMPACTS flight, the King Prove Slave voltage started with 5.21 volts before take off. After take off, and during the rest of flight the Slave voltage was between 6.1V to 6.2V, which is above the usual 5.0 Volts. Additionally, the LWC value for the King was steady during flight at -0.4 g/m^3.
Solution
01/18/2022. The slave negative and signal negative was labeled incorrectly for the analog to digital board wiring.
- Blue and White wire - Slave high
- Orange and White wire - Slave low
- Black and White wire - Ground (Disconnected)
- All White wire - Signal high
- Green and White wire - Signal low
Problem
Low Slave Voltages (11/11/2022 - Jennifer Moore). After installing King probe on hot-wire boom during NASA IMPACTS integration, noticed that the M300 was not receiving data from the King. Before probe installation on 11/08/2022, the harness was tested for 28VDC. Additional wire testing was done after noticing no data on M300. All wires going from wing to rack pin out properly, and all wires going from wing to probe pin out properly. A test was done on the sensor wire showing that the slave pins and master pins were all good- the hot-wire sensor does not need to be replaced. It is good to note that during a wire test from the 'king meter to A/D board' wire and the harness coming from wing to king meter box there was only two of the four pins completing the circuit (SL- and Sig-).