accuracy humidity Model 609

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  • Updated 9 months ago
Humidity reads 13% different between indoor and outdoor sensors (when sensors are next to each other)
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Joel Sandberg

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Posted 9 months ago

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I have something similar, 5 different sensors, all next to each other, with a range of 35% to 38% depending on which sensor you look at.  What are the tolerances supposed to be?  Joel, your's seems much worse, maybe hardware error?
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Joel Sandberg

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There is a specification stated for the RH of the 609 (I found it on the Acurite web pages) and you are well within the limits of their claims.  Based on my base experience, to get any better/tighter reading would cost hundreds of dollars per gauge (use a wet/dry bulb sling hygrometer) .  Acurite spec is +/- 4% gauge to gauge for RH, and +/- 3 degrees for temp - both very respectable for this price gauge.
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AcuRite Jennifer

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Hello Joel,

When you are comparing the readings you want to let them sit side by side for 30 minutes without touching them. After the 30 minutes you want to compare the readings. If you are comparing 2 AcuRite products together the total difference between the 2 for humidity can be 10% difference. The accuracy standard is +/-5% on each device.  Make sure you are following the battery guidelines below:

You want the display and sensor to be at least 3 feet from electronics such as televisions, microwaves, computers & radios.  Follow the battery guidelines below:

•Verify you are using fresh alkaline batteries or lithium batteries (when temperature is below -4oF/-20oC) in sensor.

•Quality brand batteries are recommended, including Duracell, Rayovac, Energizer, or Kirkland.

•Verify batteries are fresh. The battery expiration date should be at least 6 years out. Batteries can lose 3% power or more every year in storage.

•Heavy duty, extra strength or generic / store brand batteries are not recommended for use with AcuRite products because they may cause performance irregularities due to the way these types of batteries disperse power. Each battery should not exceed 1.6 volts.

•Rechargeable batteries are not recommended for use with AcuRite products because they may cause performance irregularities due to the voltage instability of these types of batteries.

•Mixing different battery types (brands, old/new, etc.) is not recommended.

If you are getting readings outside of the standards we would recommend doing what we call a hard reset. The hard reset steps below are based off the 00609 model number that I assume you were providing. These are for a thermometer that does not have the A-B-C switch in the battery compartments.

1. Bring both the sensor and display unit indoors and remove the batteries for at least 2 minutes.
2. Reinstall the batteries in the outdoor sensor.
3. Reinstall the batteries in the display unit.
4. Let the units sit within a couple feet of each other for about 30 minutes without touching them. Compare the readings after the 30 minutes.
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Joel Sandberg

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I have tried the steps you outlines twice. 
The problem is still t he same.
The indoor relative humidity is 14% higher than t he outdoor RH with the sensors next to each other (and indoor, not near any heat generating equipment).
I also have three model 619 monitors.  The RH of the thee 609 is the same (+/- 2%) of the outdoor RH from the 609.
All five temperatures are acceptably close.
It still looks like the Indoor RM sensor for the 609 instrument.

Do I return it to the Lowes store I purchased it from, or does the factory replace the defective unit?
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Joel Sandberg

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Clarification and trying to correct typos.

I have tried your suggestions (both before and after receiving your reply).
The indoor RH still reads 14% higher than the outdoor RH.
The indoor display and the outdoor sensor are next to each other inside an air conditioned house, 20 feet from any heat generating source (TV, computer, etc).
I also own three model 619 units.
All three 619 units read about the same RH as the outdoor sensor of the 609 (+/- 2%).
All five temperature readings are very close to on another (+/- 1-2 degrees)

Do I return the 609 to the Lowe's store I purchased it from or does the factory make the corrections/replacement?
Or . . .
Is there any adjustment (poteniometer) inside that I can adjust using the 619s as my base line/standard to go by.  I know this would take some trial and error and would take a few hours to adjust/settle/adjust/settle etc.
I do not know if all of the components inside are fixed or if there is any way to calibrate the indoor RH reading against a "standard".

Thank you.

Joel Sandberg
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AcuRite Rachell, Employee

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Hello Joel,

We have emailed you at the email address associated with your community forum account.  Please check your inbox. Thank you.