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An affordable high
resolution isoperibolic temperature regulated oxygen bomb calorimeter
with embedded control computer.
The bomb calorimeter is the most common device for measuring the heat
of combustion or calorific value of a material. With this apparatus a
test specimen of specified mass is burned under standardised conditions.
The heat of combustion determined under these conditions is calculated
on the basis of the observed temperature rise while taking account of
heat loss. The combustion process is initiated inside an atmosphere of
oxygen in a constant volume container, the bomb, which is a vessel built
to withstand high pressures. It is immersed in a stirred water bath, and
the whole device is the calorimeter vessel. The calorimeter vessel is
also immersed in an outer water bath. The water temperature in the calorimeter
vessel and that of the outer bath are both monitored.
The FTT Oxygen Bomb
Calorimeter can be used to measure the heat generated from several applications
and has been designed to conform to current ASTM, ISO, EN, BS and DIN
international standards. The calorific value of the following groups of
materials can be measured: -
•
Building materials (e.g. EN ISO 1716)
• Coal, coke (e.g. ASTM D 3286)
• Fuel (gasoline, kerosene, fuel oil, No.s 1-D and 2-D diesel
fuel and No.s 0-GT, 1-GT, and 2-GT gas turbines fuels)
(e.g. ASTM D240-92)
• Hydrocarbon fuels (e.g. ASTM D 4809-90)
• Food, supplements, crops
• Waste and refuse
• Combustible materials, etc.
Isoperibolic
Operating Mode
An isoperibolic bomb calorimeter is a calorimeter where the jacket temperature
is kept at a constant temperature while the calorimeter vessel (bomb and
bucket) temperature rises as heat is released by the combustion of a sample.
The jacket and bucket temperatures are continuously measured enabling
the heat loss to be corrected for after the test.
An
embedded control computer, keypad and LCD enables instrument automation,
data acquisition and analysis via user friendly menu driven software.
Automatic Temperature
Control of Outer Bath
The embedded control computer automatically sets the outer bath temperature.
The temperature is measured using two high precision, high resolution
platinum resistance thermometers (PRTs). An external thermostatic controller,
bath, circulator and cooler is supplied as standard together with a pipette
for temperature controlled filling of the calorimeter vessel. This removes
human error increasing repeatability and significantly reduces the preparation
time between tests.
Oxygen Filling System
To simplify instrument operation the FTT Bomb Calorimeter is fitted with
a semi-automatic filling system. The user merely connects the push on
coupling and presses the key to fill the bomb with oxygen. The bomb then
fills to the desired pressure and automatically switches off. If this
pressure is not reached an error message is shown.
Automatic Firing
The embedded computer controls the temperature of the outer bath and shows
when the calorimeter vessel temperature has stabilised. At this point
the bomb is automatically fired.
Calibration
The FTT bomb calorimeter is calibrated by burning certified benzoic acid
to determine a constant called the ‘water equivalent’. The
instrument can record the water equivalent for several bomb/bucket combinations.
For each bomb/bucket combination five calibrations are performed. The
software calculates the average of these five calibrations and uses this
value as the water equivalent when testing a sample.
Ordering Guide
The FTT Bomb Calorimeter consists of: -
Bomb
calorimeter with embedded computer control, user-friendly interface, LCD
graphics display, high accuracy / resolution PRTs, 2 x RS232 interfaces,
parallel port for printer.
• Oxygen bomb and bucket (calorimeter vessel)
• Thermostatically controlled bath, circulator, cooler, pipette
(2L)
• EN ISO 1716 sample preparation device, firing wire
& cotton, cigarette paper
• Accessories for installation
Optional accessories: -
• Spare oxygen bomb
• Corrosion resistant oxygen bomb (corrosion resistant to
halogen gases)
• Printer
• Bucket
• Benzoic acid, 100g
• Nickel Chrome Crucible
• Nickel Chromium Firing Wire 25m length
• Analytical Balance
• Firing cotton
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1) Stirrer
2) Calorimeter bomb
3) Jacket
4) Calorimeter vessel
5) PRT
6) Ignition lead
7) Jacket lid
Services
• Electrical supply, 115VAC, 6A,
50/60Hz or 230 VAC, 3A, 50/60Hz
• Distilled water
• An oxygen supply is required at a
pressure of between 28 and 35 bar
• Cigarette making paper
Dimensions
(lxwxh, mm)
FTT Bomb Calorimeter: 420x360x540;
Tank and controller: 350x325x355;
Cooling system: 460x305x225:
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