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View Full Version : Meter Calibration and Conversion Factors



Unregistered
08-18-2006, 08:13 PM
Well, I've managed to keep most of my plants alive for 2 weeks, despite my best efforts to mess things up royally. I'm trying to be diligent, water changes weekly, daily testing of pH and nute levels. And weekly meter calibrations to ensure accurate readings which leads me to my question. I have a Hanna HI91289. In order to calibrate it with the 1413 solution, I need to set the conversion factor to 1. Is this the correct conversion factor to measure the solution ppm or after calibrating to 1413 am I to change the conversion factor to 0.5?

The reason I ask is I changed the water 2 days ago, set the pH and got a meter reading in the low 300 ppm (where I wanted it to be). Today I was calibrating my meter and noticed it was saying to use 1382 for the EC calibration (conv was at 0.5). I reset the conv. factor to 1 and then tried calibration again and the meter said use 1413, the solution hanna recommended for this meter. Calibration was successful. I went to measure my system, had to lower the pH slightly and then read the ppm's and they were in the 700 range. I removed a lot of the solution and replaced with plain water until it was reading in the mid 300's. Which measurement was the accurate one? The one where conv factor = .5 from 2 days ago or the one where the conv factor = 1 from today?

Obviously, to calibrate to 1413 the meter's conv. factor must = 1. When measuring my solution for pH and ppm, what should the conversion factor be set to? I'm concerned that I'm now starving my plants because I am not using my meter correctly. Any info on using my hanna meter would be greatly appreciated. Thanks in advance for you advice.
-prplmtngal

dhill
08-23-2006, 03:24 PM
Firstly the 1413 is for calibrating the meter in S. To calibrate your meter in ppm adjust the conversion factor to 0.7 and purchase 1500ppm (http://www.bghydro.com/BGH/Itemdesc.asp?ic=TECSTDS15-08&eq=&Tp=) calibration solution. Once your meter is calibrated in this way it will be ready for use.

MisterMiyagi
07-19-2007, 12:54 PM
DHill: Could you explain what Beta is and what it should be set to?

Unregistered
01-11-2012, 01:08 PM
I second the above users question.. whenever testing with that 1500ppm solution. Is the beta still to remain at 1.9 or do u change it to 2.1?