Aluminium Strip Thermometer – AST
The Land Aluminium Strip Thermometer system is specifically designed to provide the aluminium hot rolling industry with a solution to one of its most difficult problems – accurate and reproducible temperature measurement of bright, semi-finished hot alloy strips. AST is capable of providing more accurate temperature measurement than any other thermometer available.
It is capable of providing more accurate measurement of temperature than either a single or dual ratio wavelength thermometer.The AST is highly effective in the measurement of temperature at both entry and exit of the Finishing Mill, the ‘Breakdown Mill’ (Reversing Rougher) and at the Downcoiler.
The AST can be used to reduce re-annealing and finishing costs and improve process control. The AST is used with the application dedicated LMG AR processor.
Applications The AST is highly effective in the following mill locations:
- Measurement at both entry and exit of the Finishing Mill.
- Measurement at the Breakdown Mill (Reversing Rougher).
- Measurement at the Downcoiler.
Optimisation As a result of experience gained from many site trials and installations, it has been found that slight variations are required in the temperature calculation coefficient values, in order to maximise the system accuracy at each measurement point. A unique feature of the AST thermometer is the ability to optimise each unit individually. This may then improve the measurement accuracy at each location. Optimisation requires a small number of temperature comparisons to be made on a representative sample of product types, against the AST set-up unit. Optimisation is performed using APCOS (Application Processor Configuration and Optimisation Software), provided as standard with the LMG AR processor. APCOS processes data and submits a relevant solution for the temperature calculation.
|Measurement range (specified):||Mill entry: 300 to 550 °C
Mill exit:: 250 to 400 °C
|Response time:||1s to 98%|
|Target size:||98mm at 2m|
|Absolute accuracy:||Better than 10 °C after optimisation (in application)|
|System output:||0 to 20mA or 4 to 20mA
(nominal load resistance 500ohms, max load including wiring 600ohms)
|Surface emissivity indication:||0 to 20mA covering emissivity range 0.00 to 1.00
Nominal load resistance 500 ohms, max load including wiring 600ohms)
Alarm relays: contact rating 50V a.c./ d.c. at 0.5A max
|Output update time:||30ms (thermometer channel output)
500ms (maths card output – optional)
|Vibration:||3G any axis, 10 to 300Hz|
|Processor type:||LMG AR (1 to 4 thermometer I/O channels)|
|I/O card type:||AST I/O card|
|Power requirements:||110 to 120V a.c. or 220 to 240V a.c., 48 to 62Hz, 35VA (max. with 4 thermometers)|
|Signal Processing Functions Time average:
||63% time constant adjustable 0 to 500s|
|Ambient temperature limits:
|5 to 45 °C
5 to 50 °C
|0.8 kg approx
3.6 kg approx
|EMC:||EN 50-082-2 (immunity),
EN 50-081-1 (emission),
For recommendations on thermometer sighting and mounting, refer to LAND.