Indoor air quality monitors or IAQ meters are subject of much research as indoor air pollution has become a major health concern. This is particularly debilitating for workers, school children and a major part of the population who spend 90% of their time indoors. So you need to select an IAQ meter of all the indoor air quality monitors that has the best specifications. If you are confused here is help for you-

Do the temperature and humidity sensors on my indoor air quality monitor need to be calibrated?

There is no field calibration needed for the temperature and humidity sensor, however these sensors will undergo verification testing when your aq-5000/ 50001 is sent in for factory recertification.

How long can the AQ-5000/5001 record?

The aq-5000/5001 has enough memory to store 57,344 data points. For example, with 3 channels (CO2, Temp and Humidity) recording data points every minute the unit can record for 13 days and 6 hours.

What are the recommended calibration gases for the CO2 sensor ?

To zero the CO2 sensor you should use Nitrogen (N2). For the span of the CO2 sensor you need to consider what range you want to monitor. The aq-5000/5001 CO2 channel can be programmed for either 5000 or 20,000 ppm full scale. For the 5000 ppm full scale range we recommend using 1000 or 5000 ppm CO2. For the 20,000 ppm full scale range we recommend using 10,000 ppm CO2.

How do I set the date and time on my aq-5000/5001 ?

The date and time of the aq-5000/5001 are set automatically when the unit is programmed using the software package. Using the software, simply create a new or view an existing setup file, program the recorder and the date and time from the computers real time clock are sent to the aq-5000/5001. The aq-5000/5001 date and time will now match the computer from which it was programmed.

I just finished calibrating the CO2 sensor on my aq-5000/5001 and the reading is very unstable, what could be wrong ?

In most instances unstable readings are a direct result of the user calibration. In some instances users have the incorrect gas attached to the unit when they press the enter button. In other instances they have set the CO2 span level to a number that does not match the CO2 span gas being used. In any instance the unstable reading should be corrected by simply performing another calibration being sure to do the CO2 zero first and then the CO2 span. Because of interaction between the zero and span it may be necessary to zero and span the unit and then zero and span the unit a second time. This will usually return the reading to a stable condition.

How does the aq-5000 Pro Calculate Dewpoint?

Dewpoint = eighth_root( RH/100 ) * ( 9*Temp/10 + 112 ) - 112 + Tc/10

where:
RH is the relative humidity in percent
Temp is the temperature in degrees Celsius

What is STEL?

STEL is a 15 minute rolling average (that rolls each minute). This means that the average reading is calculated after the first 15 minutes of logging and then again after each subsequent minute of logging. At the completion of each subsequent minute, the new 15-minute average is compared with the old and the higher of the two is stored and displayed.

What is TWA?

TWA is an average based on an 8 hour interval. The average is taken by summing all of the the samples taken and dividing by the number of samples in 8 hours (28800 for the aq-5000 Pro). The important thing here is that the average is calculated the same way regardless of whether you've run the instrument for 1 hour, 8 hours, 24 hours or any other amount of time (i.e. the number of samples used to divide by is the same).