Lovibond Iron LR Checkit Disc 0-1 mg/l FeLovibond Iron LR Checkit Disc 0 1 mg l Fe Each CHECKIT Comparator Disc contains a continuous colour scale for exact colour matching between standard and sample. Lovibond Iron LR Checkit Disc 0 1 mg l Fe The Iron disc supplied measures from 0. 05 1 mg l with the following steps: 0. 05 0. 1 0. 15 0. 2 0. 25 0. 3 0. 35 0. 4 0. 45 0. 5 0. 55 0. 6 0. 65 0. 7 0. 75 0. 8 0. 9 1. 0