The linear dynamic range is the key technical index is very important. Analysis of worker total hope HPLC UV detector does not need to concentrate on very dilute samples or on very thick samples do not need to be diluted can directly test, and reach the requirement of error. Unfortunately, the current international HPLC UV detector manufacturers rarely gives the LDR, this will give the job to bring error analysis. So, HPLC UV detector manufacturer should be carefully tested and truthfully give instruments LDR.