**4.4. Differentiation of blood stains**

Blood is a substance that absorbs IR rays.

Yazımı düzeltilmiş şu sorgu için çevirileri görüyorsunuz: Dolayısı ile olay yerinde *kızılötesi* dalga boylarını kaydeden bir cihaz kullanılması neticesinde kan lekelerinin fark edilebilirliği artmaktadır.

Yine de girdiğiniz şu sorguyu mu aramak istiyorsunuz? Dolayısı ile olay yerinde kızıl ötesi dalga boylarını kaydeden bir cihaz kullanılması neticesinde kan lekelerinin fark edilebilirliği artmaktadır.

Thus, the differentiation in the availability of blood stains in crime scenes increases when using a device noting IR wavelengths. This method is advantageous for precisely determining the morphology of blood stains. Furthermore, this method reduces the number of samples obtained from the crime scene depending on the quicker determination of materials at the crime scene and prevents the time spent and economic losses [16, 52]. Two studies demon‐ strated that in the detection of blood stains with an IR camera, better results were obtained by other methods even in blood stains 10-times diluted or found on the floor, which absorbs blood [16, 52]. In another study performed by Lin et al., blood stains diluted to a 1/8 ratio were viable in 8 of 10 different cloth samples by IR photography. Nevertheless, blood stains diluted to a 1/2 ratio were not viable in two fabric types, including 35% rayon and 65% polyester and 5% lycra and 95% cotton, via IR photography [48].

It has been reported that the determination of blood samples and the identification of their ages on fabrics are possible using IR cameras. In the identification of the ages of blood samples, the cross-validated standard error of calibration was less than 1 week in optimal conditions [53].
