I'm not sure if you've rented a PAR meter,good luck. However, I'd like to recommend a PAR meter that is both inexpensive and practical.
As shown in the picture, it is equipped with a waterproof probe and a extension rod of 2.95ft, which enables you to extend it into the water for measurement. The price is around $140, much lower than that of some well-known brands, but the measurement results are almost on a par with those of the latter. It offers excellent value for money. I hope this information is helpful to you.