A Measurement System.
Standard Gauge Offer:
- One Scanning O-Frame with two X-ray Fluorescence sensors (for measurement on both sides of the strip).
- Latest Computer Control and Display Station 15" (Optional other sizes) with Intel Pentium Latest Processor. Color Printer Station from reputed company.
- Software Package for Data presentation, reporting and trend reports.
- Analog and Digital Input/output Modules for Line Speed Input, Alarm Output, Control Output(s).
- Coil Report Package.
- Services relating to Erection & Commissioning and acceptance testing of gauge.
System General Description:
XRF 3000 Coating Weight Gauge provides accurate, high speed non-contact and non-destructive measurement of Zinc coatings applied on steel strips. The complete system can be sub-divided into following :
The system uses X-Ray florescence based two measuring heads coupled along with ionization chamber detector units. These two measuring heads give highly accurate coating weight measurement corresponding to top & bottom of the zinc coatings applied on base steel strip. The measuring heads operate under a high performance PC based control unit thus giving rapid response measurement of coating weight.
Scanning O-Frame :
The measuring heads are mounted in O-frame scanner with proven technology. O-frame is available in various sizes depending upon the strip width requirements.
- Single point measurement - The measuring heads can be positioned at any point across the strip width. In this mode, the coating gauge measures the machine direction trend of the coated weight.
- Continuous Scanning Mode – In this mode the measuring heads are continuously scanning from edge to edge of the strip. After each scan, the cross profile is displayed on the operator screen.
- Triple Spot Measurement - In this mode, the measuring heads are positioned in cycles, such that measurement is carried out at a selectable distance from left strip edge, at center line & at a selectable distance from right strip edge.
Coat weight is averaged during the measurement period & displayed as a Trend on Operator's screen.
GAUGE ELECTRONICS :
The front end electronics is mounted in a cabinet along with O-frame & houses main electrical components as well as scanner processing electronics. An Ethernet cable is used to connect this front end electronics cabinet to the main electronics console which is generally kept inside the control room, the gauge is also equipped with large size radiation lamp.
GAUGE OPERATION :
The operator has overall control of measuring system via workstation attached with keyboard. The display on the screen allows the operator to have access to all the measuring system features via an user friendly operator control interface thus assuring easy operation. Moreover, the coating weight profiles, production reports, system errors / diagnostics also appear on the operator screen.
GAUGE STANDARDIZATION :
The standardization is initiated either manually or automatically under the control of system computer on a predetermined time basis. The measuring heads are automatically sent off the strip and made to measure on a reference sample, disturbing influences such as drift and dirt on sensor windows are thus eliminated.
GAUGE CALIBRATION :
The calibration is done on the measuring system during manufacturing. Also, recalibration is done during commissioning of the system at customer site. For calibration purpose, customer provided coated samples are used.
PRINTER STATION :
The measuring unit comes with colored ink jet printer station. All the displayed information on monitor can be also be printed. Moreover, the detailed coil reports can be printed as & when required.
Typical Payback Calculation Example:
| Production Data : |
|Strip Speed ||150mpm |
|Strip Width ||1000mm |
|Target Coat Wt. ||90GSM ; ± 5GSM |
| Without Zinc Coating Gauge : |
|Actual Avg. Coating Weight ||100GSM |
|Typical Variation ||± 10GSM |
| With Zinc Coating Gauge : |
|Operator can keep the coating within set target Coat weight of 90GSM to ±5GSM |
| SAVINGS : |
|Avg. Saving : ||10GSM |
|Savings per minute : ||(10*150*1)/1000 = 1.5kg/min |
|Savings per day : ||(1.5*60*24)/1000= 2.16T/day |
|(A typical Pay Back can be achieved in a target frame of six months of continuous running.) |
| || |
|Sampling Time ||20msec. |
|The time interval over which digital Information is collected. |
|Overall Integration Time ||2sec. |
|The time interval over which the numerical Values of Coating Weight are averaged. |
i.e. Variation of the output signal under reference conditions, while all influence quantities are held constant.
| Accuracy Range Table |
|At 50g/m² ||± 0.15g/m² |
|At 100g/m² ||± 0.25g/m² |
|At 150g/m² ||± 0.45g/m² |
|At 200g/m² ||± 0.70g/m² |
|At 250g/m² ||± 2.00g/m² |
|At 300g/m² ||± 3.50g/m² |
Reproducibility shall be tested in OFF-SHEET position on the basis of samples provided by customer. All data related to samples shall be of known coating weight & with same composition of coating. Also the samples should be with known thickness & with same alloys of substrate. These Samples need to be provided by the customer.
In principle, it has to be considered that Accuracy depends on the number & quality of samples provided by the customer.
Overall Instability ( Drift ) : + 0.5% in 8hrs.
i.e. Long term variation of the output signal under reference
conditions , while all influence quantities are held constant.
Measurement Area : Approx. 70mm in diameter.
Standardization Frequency : Recommended after every 8hrs.
Standardization Time : Approx. 75 seconds ( after shutter is open)
Initial warm up from cold start : Approx. 30 minutes.
Operating Temp. Range : Electronics Cabinet up to 35°C & O-Frame : Normal CGL conditions.
- The Gauge measuring sample design required to measure square shape sample approx. 100 x 100mm or round dia. of 100mm.
- The System has provision for level 2 connectivity, provided the relevant Protocol is available from Customer system.
Coil Report Package:
- Length wise trend report
- Historical Data Trends / Production Reports
- End of Coil Status
- Coil Histogram
- Tolerance Segments
Coating Thickness Gauge.