There's alot of airsoft/Airguns chronos for sale on the internet. Many of them goes for 50-60£. Some products:
COMBRO CB-625 Mk4 Air Rifle Gun Chronograph
Airsoft Chrono Chronograph Genuine XCortech X3200 MK3
E9800-X Shooting Chronograph Airsoft BB Speed High-Precision

Anyone have any experience with these. Are they ok for just measuring the muzzle velocity of my airrifle?