ph & chlorine test meter -can someone help me to calibrate it

i bought this "electro tester" a few seasons ago. It runs on one AA battery and I don't have the directions to calibrate it anymore. can anyone help?
Thanks

what make and model?

well, that's a good question. it's an inexpensive one and there's not much identifying info on it. (I think it was about $20 if I recall). All it says is "Electro Tester Ph & Chlorine for Pool and Spa". The company is World Industries International. There is no model, nothing. I tried googling for the company, but no luck. It works, but the readings need to be adjusted.

personally, I would not trust a $20 pH and ORP meter to provide any kind of accurate results! Most halfway decent portable ones such as the LaMotte are in the neighborhood of $100! I did find these instruction for calibration on Ebay where it was being sold. From what I know of pH and ORP meters this unit doesn't seem like it will produce accurate results. I personally would not trust it!

"See Below for 3 Simple Steps to the Perfect Pool
1. Calibrate your New Tester
Test your pool for the very last time with your old-fashioned chemical kit and record the level of chlorine you prefer
Insert your brand new pool tester into your pool up to the black-coloured section of the prongs and gently stir the water
Keep the probes in the water, turn the tester wheel round to ‘CL’ then slowly turn back to the right until the needle points to the level that you recorded with the chemical kit
Take the tester out of the pool and the needle will swing to the right and will rest on a letter between ‘A’ and ‘E’ – this indicates your adjustment point
2. Test the Level of Your Chlorine
Wait for a couple of days until your pool is ready to have the chlorine tested
Turn the tester wheel until the needle points to your adjustment point
Place the probes in the pool and the needle will move to a position on the dial
Read the instructions! If you need chlorine the tester will tell you. Add little by little until the needle stops in an ideal range
3. Test your PH Levels
Place the probes in the pool and turn the wheel towards ‘PH’ until you hear a click
The needle will move to display the PH level – as with the chlorine, follow the instructions and gradually alter your levels if need be.
Enjoy your swim!"