Working Principle of CRB Probe in Aircraft

CRB ProbeThere are many parts and components in an aircraft that do not generate their own heat and instead, rely on heat generated from the engine. Of all these non-heat-generating components or parts, the aircraft carburettor is perhaps the most vulnerable to humidity and low temperatures. The freezing of the aircraft carburettor would not just impede the smooth functioning of the engine, it will ultimately stop the engine from functioning!

To prevent the above from happening, an anti-icing system that preheats the air before it reaches the carburettor is put in place. This is intended to keep the fuel-air mixture warm enough so that freezing does not occur and the carburettor is kept free of ice. Despite this, higher humidity levels coupled with abnormal temperature variations when flying in certain locations and height, can cause the carburettor temperature to drop and ultimately freeze.

As the ultimate fail-safe, the pilot(s) must be able to detect temperature drop of the carburettor and this is achieved via the Carburettor Temperature Probe (CRB) connected to the Aircraft Engine Data Management (EDM). When temperature drops, pre-heat can be switched on to prevent the freezing of the carburettor.

Carburettor Temperature Probe is a sensor mounted directly on the carburettor wall and detects temperature drop. This, along with other indicators (e.g. rough sound, drop in rpm etc) serve as a warning to the pilot(s) of impending disaster.

Modern CRB probes especially those manufactured by J.P. Instruments, are meant to withstand effects of humidity, oil, gasoline, as well as wide temperature variations. The sensing coil within the CRB is fully coated in an epoxy resin which itself is within a metal tube thick enough to withstand repeated backfires, but thin enough to be highly sensitivity to temperature change.

When the CRB probe is fitted, care should be taken to fit it gently but firmly and without using harsh tools such as pliers. The tightening torque should be no more than 4 foot-pounds. Only one spacing washer can be used, and should contact the carburettor casting, with the lock washer in contact with the shoulder on the probe. Allow sufficient slack for the wires of the probe.

If the probe does not reach all the way into the carburettor barrel, the counterbore can be used again to reduce the thickness of the casting slightly at the outside of the hole. Recommended torque is 3 to 4 foot-pounds as anything more than this will likely damage to the threads in the carburettor or the probe. For more information on aircraft CRB Probes, please visit


Features and Specifications of EDM 350 Experimental System

EDM 350 Experimental SystemThe EDM 350 Aircraft engine data manager by J.P. Instruments measures precisely 3.25 square inches i.e. smaller than a standard sized stapler and yet, it this little gadget is packed with electronic chips that analyse over 2 dozen different engine parameters of any 4-cylinder aircraft. The basic 4-cylinder kit starts at just $798 while the 6-cylinder kit is priced at $988. Both representing true value for money.

Fitting the EDM 350 is as easy as can be. All you need is a 3.25 square inch empty space. First attach all the probes to the engine and thread them out of the empty space, similarly add the wires. Next attach the probes and wires to the EDM 350 and ‘plug-in’ the EDM 350 Aircraft engine data manager into the empty socket. That it, you’re good to go.

Features and specifications of the EDM 350 experimental engine data manager by J.P. Instruments includes the following measurements and display:

1. EGT – Exhaust gas temp.
2. CHT – Cylinder head temp – probes and harness included.
3. VDC – Voltage display.
4. CLD – Shock cooling on all cylinders.
5. ROP/LOP – Lean finder.
6. DIFF – Engine health.
7. USB Port – Convenient data port for quick and easy download of engine data.
8. Internal Memory – Enough memory to record 600 hours of data (recorded every 6 seconds).
9. EZTrends Software – Graphics software with Google Earth location included.
10. RPM – Prop rotation speed.
11. MAP – Engine Manifold pressure.
12. O.T. – Engine oil temp.
13. O.P. – Engine oil pressure.
14. F.P. – Fuel pressure.
15. OAT – Outside air temp.
16. TIT – Turbine inlet temp.
17. CRB – Carburettor temp.
18. CDT – Compressor discharge temp.
19. AMP – Battery load output in amps.
20. L-R-Main – Fuel quantity in all tanks.
21. V-2 – Second volts readout.
22. Amp-2 – Second load readout in Amps.
23. % HP – With FF, OAT and RPM Sensor.
24. FF – Fuel flow includes:

• GPH – Gallons per hour.
• REQ – Fuel required to way point / destination.
• USD – Fuel used.
• H:M – Endurance in hours and minutes.
• MPG – Miles per gallon


1. EGT Gauges must be mounted 2 to 4 inches from aircraft cylinder head.

2. If EGT clamps are too short, please buy larger clamps (available with J.P.I)

3. If EGT Probes appear to be lose, please remove the probe, squeeze the thimble and reassemble.

4. Existing TIT Probe cab be used only if the aircrafts TIT probe has the same type thermocouple.

For more information on EDM 350 Aircraft Engine Data Management by J.P. Instruments, please visit:

Importance of Engine Monitors & Engine Gauges in Aircraft

Engine Monitors & Engine GaugesImagine flying an aircraft with no engine monitors or engine gauges. As a pilot, you wouldn’t know what is happening in the engine compartment – whether the cylinders are over-heating, whether an engine starved of fuel, or, whether the aircraft engine is about to suffer a catastrophic failure that could end your flight in total disaster!

Aircraft engine monitors and aircraft engine gauges are a set of instruments located in the cockpit of an aircraft. These engine monitors and gauges supply the pilot with data regarding the health of the engine and its current performance in real-time.

Every engine be it an aircraft engine or any other engine, has certain manufacture determined safe parameters within which the engine has to operate. Any deviation could lead to a catastrophic failure of the engine.

These days, manufacturers of engine monitoring systems and engine gauges (e.g. J.P. Instruments) not only make aircraft engine monitors and engine gauges that display real-time engine information, they also have built-in artificial intelligence to warn the pilot(s) if any engine parameter are not in conformity of safe operating limits.

For example, if the aircraft engine temperature or engine pressure where to exceed pre-specified limits the aircraft engine monitor will bring this to the attention of the pilot(s) via audio-visual indicators such as flashing / blinking and sounding load audio beeps.

Also, these days manufacturers such as J.P. Instruments have gone a step ahead and inserted memory cards within the engine monitors. Additionally, maintenance crews and pilots can not only interact directly with the instruments by updating engine parameters via the user interface, they can also download engine data via convenient USB / serial ports. This data can then be analysed by the ground crew. Such data is also of vital importance to manufacturers and insurance companies who are called in after some engine related incident.

Some of the engine monitors and engine gauges include RPM Sensor counter, engine pressure and temperature gauges, fuel level and fuel flow gauges (one set per engine), exhaust gas temperature and so forth. Every little thing has to be monitored which is why until recently, an aircraft cockpit used to look frightening with dozens of dials and knobs crammed into every nook and corner of the cockpit. But thanks to aircraft engine monitor manufacturing companies such as J.P. Instruments, a modern upgraded aircraft looks more like a gamming room with just a few futuristic looking LCD/LED screens and a dozen dials.

These LCD/LED screens are called ‘EDMs’ short for Aircraft Engine Data Management. These EDM’s have replaced almost all the monitors and gauges. So instead of attempting to looking at dozens of different dials, the EDM monitors the different parameters of the aircraft engine and displays critical information via the LCD/LED screen. These EDM also warn the pilots if any engine parameter exceeds pre-determined limits.

Engine Data Monitor 930 System vs EDM 900

Engine Data Monitor 930 SystemThis article provides you with relevant information to compare EDM 930 and EDM 900 aircraft engine data monitoring systems manufactured by J.P. Instruments.

As you will see, while appearing to have similar specs, the EDM 930 is a far more advanced product over the EDM 900.

EDM 900
From $3,695.00 to $4,965.00)


Aircraft Engine Monitoring
Aircraft Manifold Pressure
Aircraft Engine Percent of Horse Power
Aircraft Engine Exhaust Gas Temp.
Aircraft Engine Cylinder Head Temp.
Aircraft Engine Oil Temperatures
Aircraft Engine Oil Pressure
Aircraft Engine Fuel Pressure
Aircraft Engine Outside Air Temp.
Aircraft Engine Voltage
Aircraft Engine Current amps/load
Aircraft Engine Gallons per Hour GPH
Aircraft Required to wp or destination
Aircraft Engine Fuel used
Aircraft Engine Endurance hours and minutes
Aircraft Engine Miles per Gal
Aircraft Engine Fuel quantity, level
Aircraft Engine Shock Cooling on all Cylinders
Aircraft Engine Gami spread high low fuel flow
Memory stick 2 GB
Aircraft Engine Scanning: every 6 sec.
Graphing software: free

Hardware Included

EDM-900 ALL IN ONE Bright VGA Display
Pre-Wired Harness for all functions
All EGT/CHT probes
Oil Pressure Transducer
Oil Temperature Sensor
Oat Sensor
RPM Sensor, One required
Manifold Pressure Transducer
100 amp Shunt (2) (for Amps)
Volts pick-up V-1 and V-2
2 GB memory Download/upload stick
FloScan Fuel Flow Transducer w/firesleeve
Demo DVD
3 year warranty


1. 900-4CP-0 (4 Cyl) for No tank Primary
2. 900-4CP-2 (4 Cyl) for 2 tanks Primary
3. 900-4CP-4 (4 Cyl) for 4 tanks Primary
4. 900-6CP-0 (6 Cyl) for No tank Primary
5. 900-6CP-2 (6 Cyl) for 2 tanks Primary
6. 900-6CP-4 (6 Cyl) 4 tanks Primary
7. 900-7CP-4 (7 Cyl) 4 tanks Primary
8. 900-8CP-4 (8 Cyl) 4 tanks Primary
9. 900-9CP-4 (9 Cyl) 4 tanks Primary

More information here:

EDM 930
(From $6,280.00 to $10,082.00)


Aircraft Engine Hands-free, automatic scanning
All programming done from the Front Panel
Lean Find™ finds the first and last cylinder to peak with true
Peak detect eliminates false peaks
Displays both leaned temperature below peak and peak
Battery voltage with alarm
Aircraft Amperes (load or charge/discharge meter)
Aircraft Engine Programmable alarm limits
Normalize view
Exhaust Gas Temperatures (EGTs) to stable 1°F resolution
DIF low to high EGT with alarm
EGTs to stable 1°F resolution
Shock cooling monitored on every cylinder
Shock cooling monitored on every cylinder
User selectable index rate
Aircraft Engine Fast response probes
Non-volatile long-term memory
Records and stores data up to 30 hours
Post-flight data retrieval
Download to Palm™ Computer
Data retrieval software
Aircraft Engine Oil pressure
Aircraft Engine Oil temperature
Outside air temperature
Aircraft Engine Fuel level
Aircraft Engine Fuel Flow
Solid-state rotor fuel flow transducer
Fuel quantity in gallons, kilograms, litters, or pounds
Low fuel quantity alarm
Low fuel time alarm
GPS interface
Instantaneous fuel flow rate
Aircraft Engine Total amount of fuel consumed
Aircraft Engine Total fuel remaining
Time to empty at the current fuel flow rate
Aircraft Engine RPM and manifold pressure
Automatically calculates percent horsepower
History of extreme values during previous flight
Hobbs® timer

Hardware Included

EDM 930 Unit

Optional Accessories:


1. JPI EDM-930 (4 Cyl) No Tank System, Primary STC
2. JPI EDM-930 (4 Cyl) 2 Tank System, Primary STC
3. JPI EDM-930 (4 Cyl) 4 Tank System, Primary STC
4. JPI EDM-930 (6 Cyl) No Tank System, Primary STC
5. JPI EDM-930 (6 Cyl) 2 Tank System, Primary STC
6. JPI EDM-930 (6 Cyl) 4 Tank System, Primary STC
7. JPI EDM-930 (7 Cyl) Primary STC
8. JPI EDM-930 (8 Cyl) Primary STC
9. JPI EDM-930 (9 Cyl) Primary STC

More information here:

What Are The Features And Specifications Of EDM 700?

EDM 700Engine data management 700 which can simply be referred to as EDM 700 is a necessary addition to any aircraft. It works by continually monitoring the engine activities of the aircraft thus, leaving the pilot to fully concentrate on flying and landing the aircraft safely. With the help of the latest microprocessor technology, a total of 24 critical parameters are monitored 4 times a second which is more than can be done by the pilot.

The EDM 700 system is also able to instantly give warning when programmed limits are exceeded. This is possible because it is equipped with an up to date warning system. It is the most accurate, advanced engine monitoring system in the world that gives assistance in all engine related areas to ensure that the operations of the aircraft run smoothly.

Features of EDM 700

Some basic but important features of EDM 700 include

• Accurate trend monitoring is achieved in the normalized mode
• Presence of bus voltage to accurately detect any voltage loss from failure of the alternator
• Troubleshooting can be achieved from the cockpit with the aid of a computer that displays problem codes
• Presence of alphanumeric scanning that displays 29 functions
• 2 different modes – LeanFind mode that searches for the first last of the cylinders to peak and the PeakFind that captures the exhaust gas temperature.
• Programming is easily achieved from the from panel using just two buttons
• Accurate leaning is guaranteed fast prove response
• Temperature: It is displayed in one degree in either Celsius or Fahrenheit
• True memory: data can be downloaded from the EDM onto a laptop or palm computer.
• 29 alarms
• EGT graph has variable scaling
• Fuel flow option
• Shock cooling
• Oil Temperature check

Specifications for EDM 700

The EDM 700 system has both important and optional specifications that perform standard and optional functions.

The important standard specifications include

• Linear gauges: selectable position options
• Power connector
• Harness
• EZTrends
• Volts
• Shock cooling
• LOP/ROP Leaning Mode exclusive to JPI
• 100 hours downloadable data recording
• Exhaust Gas Temperature (EGT) 4 or 6 probes
• CHT 4 or 6 probes

The Optional Specifications Include

• Oil Temperature
• Outside Air Temperature (OAT)
• Oil pressure
• Fuel Flow – USED, Remaining, GPH Endurance, GPS destination
• 1 gigabyte USB stick for downloading data

Other specifications of the EDM 700 include

• The EDM 700 IS 2.5 x 2.5 x 8? with 2 1/4 bezel, including the connector.
• TSO C43b, Temperature Indicator EGT-701 14.5 oz. / 0.9 lbs
• Wire P.N. WK.-24 Harness 8 ft. 14.0 oz. each / 0.88 lbs
EGT Probes MM-111 2.0 oz. each / 0.125 lbs
• RPM 1.5 oz. / .094 lbs
• CHT probe 5050 1.5 oz. each / 0.094 lbs

How Do Aircraft Fuel Flow Indicators Work?

Aircraft Fuel Flow IndicatorsIt is important to check the fuel level before the start of a journey. This is necessary for any means of transportation – cars and aircrafts. This is required in order to avoid stopping and refueling alongside the delays and inconveniences that may result.

There are some devices that can be installed in an aircraft that can accurately determine the fuel level. They are necessary in order to minimize disasters that may result when an aircraft runs low on gas. These devices are called fuel flow indicators. They operate on several basic principles that are all aimed at determining the precise level of fuel in an aircraft.

Overview on how fuel flow indicators work

A typical fuel flow indicator is composed of several displays for the following items with each item represented as symbols

• Fuel used (USD)
• Fuel remaining (REM)
• Hours and minutes remaining (H.M.)
• Fuel required to waypoint and destination (REQ)
• Fuel reserve (RES)

The function of each of these symbols include

Fuel Used (USD)

This indicator shows precisely how much fuel was used after the last refueling. As the fuel level increases due to increased usage, the number displayed will increase as well. This indicator can also be programmed to show just how much fuel was used on a multi-fuel stop flight.

Fuel Remaining (REM)

With fuel indicators, the total fuel remaining in the aircraft can also be calculated. This enables the pilot to have an idea of how much longer the remaining fuel in the aircraft would last and when to refer it. The Fuel Remaining

Hours And Minutes Remaining

Fuel flow instruments are also programmed to show how long an aircraft can continue on a flight. This value is called the endurance time and it is represented in hours and minutes. The value is calculated based on the current fuel flow rate at a particular time. Variations exist in the value of the endurance time. This variation is shown in different circumstances including

• During sea-level climb: Half the actual time is shown on the indicator
• During a power reduction descent: More time than is actually available is shown on the indicator

Fuel Reserve

Based on the destination programmed on the GPS, the Aircraft Fuel Flow Indicator is able to calculate how much fuel is left in reserve when the aircraft arrives that destination.

In summary, Fuel Flow Indicators show the level of fuel in an aircraft to the pilot. This is usually necessary to prevent fatal incidents and in determining the health of an aircraft engine. The fuel flow indicators literally show any malfunctioning so that proper care and repairs can be given. Hence, they are very important pieces that must be installed on any aircraft.

Aircraft Instruments Use for Characterization Of Aerosol Optical Properties

Aircraft InstrumentsWhat are Aircraft Instruments?

Aircraft pilots cannot just look out of the window and know where they and what is going on around them. They instead rely on instruments. Instruments essentially concern measurement. Common aircraft measurements include fuel consumption, direction, position, speed, and altitude.

Aircraft instruments are basically grouped in two ways: 1) work performance; and, 2) operating principles. Instruments that measure work performance include vertical speed, altimeter, and airspeed. The basic principles of engine operation concern the relationships between the temperature, volume, and pressure of gases. Instruments that measure operating principles, therefore, include those that measure such interactions.

What are Atmospheric Aerosols?

Aerosols are minuscule, suspended particles in the atmosphere. They drastically influence climate. They impact radiative transfer by absorbing sunlight, by scattering, by altering clouds’ lifetime, amount, and microphysical structure. When they are big enough, we can see them scatter about and absorb sunlight.

How Can Aircraft Instruments be used for Characterization of Aerosol Optical Properties?

For experts to study atmospheric aerosols’ effect on climate, they need to understand their optical properties. Aircrafts have been productive in characterizing the atmospheric aerosol optical properties.

Vertical distributions of aerosol optical properties based on Avionic Instruments over the Loess Plateau were measured for the first time during a summertime aircraft campaign, 2013 in Shanxi, China. Data from four flights were analyzed. The vertical distributions of aerosol optical properties including aerosol scattering coefficients (ssc), absorption coefficients (sab), Angström exponent (a), single scattering albedo (?), backscattering ratio (ßsc), aerosol mass scattering proficiency (Qsc) and aerosol surface scattering proficiency (Qsc’) were obtained. The mean statistical values of ssc were 77.45 Mm- 1 (at 450 nm), 50.72 Mm- 1 (at 550 nm), and 32.02 Mm- 1 (at 700 nm). The mean value of sab was 7.62 Mm- 1 (at 550 nm). The mean values of a, ßsc and ? were 1.93, 0.15, and 0.91, respectively. Aerosol concentration decreased with altitude. Most effective diameters (ED) of aerosols were less than 0.8 µm. The vertical profiles of ssc,, a, ßsc, Qsc and Qsc’ showed that the aerosol scattering properties at lower levels contributed the most to the total aerosol radiative forcing. Both a and ßsc had relatively large values, suggesting that most aerosols in the observational region were small particles. The mean values of ssc, a, ßsc, Qsc, Qsc’, sab and ? at different height ranges showed that most of the parameters decreased with altitude. The forty-eight hour backward trajectories of Aircraft Sensors masses during the observation days indicated that the majority of aerosols in the lower level contributed the most to the total aerosol loading, and most of these particles originated from local or regional pollution emissions.