System Components
Temperature Control
Temperature measurement is by a single DIN 43760 Class A platinum resistance sensor (Pt100). Heating/cooling is provided by a sealed, solid-state thermoelectric heat/cool element (Peltier element). Temperature control is by a heat/cool PID algorithm built in to the microprocessor system controller. The sensor can be calibrated by the user via the built in calibration routine in the instrument software.
| Ambient temperature limits | +5.0 to +35.0°C |
| Fuel temperature control | 25.0 ±1.0 max, ±0.1°C typical |
Conditioned Air Flow Control
Conditioned air temperature and relative humidity are measured with a factory calibrated combined RH and temperature probe. Recalibration (if necessary) is catered for by a low-cost exchange of the probe for a newly calibrated unit. Dry air is supplied from a compressed air cylinder and part of the flow is humidified in a water column. All flow rate adjustment is by two precision flow controllers which continuously adjust wet and dry air flow rates to give the correct humidity and overall flow rate. A PID algorithm built in to the microprocessor system controller drives the flow controllers.
| Flow rate | 3.8 ±0.1 litres/min |
| RH | 10.0 ±0.2% indicated |
| Temperature | 25.0 ±1.0 max, ±0.1°C typica |
Motor Speed Control
Motor speed is measured by a 1000 pulse/rev encoder on the motor shaft. Control is by a PID algorithm built in to the microprocessor system controller, referenced to the microprocessor system clock.
| Motor speed | 240.0 ±0.5 rpm |
Test Cycle Control
The complete test cycle is controlled by a built in microprocessor control system. The control system stabilises the fuel bath temperature, conditions the fuel for the required time then applies the load, times the test duration and removes the load at the end of the test. No operator intervention is required other than to fit the test specimens and fill the fuel reservoir with test fuel. A single button press starts the test cycle. Fuel conditioning and test times are measured by reference to the microprocessor system clock.
| Fuel conditioning time | 15 minutes, ±0.1 second |
| Test duration | 30 minutes, ±0.1 second |
Services
Electrical
4 standard litres/min compressed air at 1 to 2 bar (100 - 200 kPa, 15 - 30 psi) inlet pressure. Air quality must meet requirements stated in ASTM D-5001 (British Oxygen Corporation BTCA 178 or equivalent)
Compressed air
Universal (100-230 VAC, 50/60 Hz, 750 VA
Air consumption
less than 200 litres per test.
Water
Air conditioning system requires 500ml de-ionised water fill after approximately 1200 test cycles.
