Cambridge College Medical Interpreter Training Graduation: Graduation Speaker

The Graduation speaker was Carolyn Ingles Director of Staff Development and Training Lemuel Shattuck Hospital. The Medical Interpreter Program Students learn how to meet the communication needs of patients and providers by becoming fluent in the vocabulary of anatomy and pathophysiology in English and in their language of origin.

how much should a Chinese interpreter charge per day in London?

I have been asked to be an Chinese-English interpreter for an auction and as tour guide for 5 full days. What is the market rate for such services?
Many thanks for responding!