Calibration of a Soft X-Ray Digital Imaging System for Biological Materials

Authors:
Kotwaliwale, N.
Subbiah, J.
Weckler, P.R.
Brusewitz, G.H.
Kranzler, G.A.
Type: Journal Article
Year of publication: 2007
Source: USDA
Collected from: AGRIS
Subject:
agricultural products
products
Description:Soft X-ray imaging of agricultural products for quality determination is gaining worldwide interest. Recent advances in technology have made it possible to capture, store, and instantaneously process digital X-ray images at higher resolution for lower cost. An X-ray imaging system was developed and calibrated to capture images with a resolution of 1024 x 1024 pixels over a 50 x 50 mm area. Maximum X-ray tube voltage was 50 kVp, maximum current was 1 mA, and signal integration time ranged from 460 to 6700 ms. The system consists of an X-ray source tube, a camera composed of a CMOS photodiode array, a frame grabber, and a data acquisition and control card. Because the X-ray beam is polychromatic, and the detector responses are variable, calibration is necessary to relate image intensity to X-ray attenuation. Imprecision of the system was 0.64% of the response range (1.63 gray level for an 8-bit pixel depth). Response, measured as mean pixel intensity, varied linearly with X-ray tube current and integration time and had a quadratic relationship with peak tube voltage. A regression model was developed to estimate blank image intensity at higher voltages and currents. Prediction and validation errors for the model were 0.46% and 1.06% (1.18 and 2.72 gray level), respectively. Beam hardening effect was demonstrated using a polystyrene target. The procedure explained in this article can be used to calibrate a soft X-ray imaging system for radiometric measurements.
 

Related Resources

An economic analysis of soilless culture in gerbera production

Provider: 
Subject: 
products
agricultural products
plant products
agriculture
agricultural practices

Exploring organic cherry investment opportunities for Greek farmers

Provider: 
Subject: 
products
agricultural products
plant products
agricultural policies
agricultural and rural legilslation
organic agriculture

Assessing the economic efficiency of a soilless culture system for off-season strawberry production

Provider: 
Subject: 
products
agricultural products
plant products
economics
agricultural economics
agriculture
agricultural practices

Thom's Commercial Directory, 1979, Pg.829

Provider: 
Subject: 
agricultural products
products

general framework for the quantification and valuation of ecosystem services of tree-based intercropping systems

Provider: 
Subject: 
agricultural products
products
agriculture
farmers
Collected from: 

Steam processed broccoli (Brassica oleracea) has higher antioxidant activity in chemical and cellular assay systems

Provider: 
Subject: 
agricultural products
products
Collected from: 

AGRERI Library

An economic analysis of soilless culture in gerbera production

Provider: 
Subject: 
products
agricultural products
plant products
agriculture
agricultural practices

Exploring organic cherry investment opportunities for Greek farmers

Provider: 
Subject: 
products
agricultural products
plant products
agricultural policies
agricultural and rural legilslation
organic agriculture

Assessing the economic efficiency of a soilless culture system for off-season strawberry production

Provider: 
Subject: 
products
agricultural products
plant products
economics
agricultural economics
agriculture
agricultural practices

External Library

Thom's Commercial Directory, 1979, Pg.829

Provider: 
Subject: 
agricultural products
products

general framework for the quantification and valuation of ecosystem services of tree-based intercropping systems

Provider: 
Subject: 
agricultural products
products
agriculture
farmers
Collected from: 

Steam processed broccoli (Brassica oleracea) has higher antioxidant activity in chemical and cellular assay systems

Provider: 
Subject: 
agricultural products
products
Collected from: