IEQ Chek
Operation Manual
12
1509-9001 Rev 1
5. MENU FUNCTION DETAILS
5.1. Calibrate Menu
Pressing the MENU button when CALIBRATE is selected accesses the calibration
menu. The LCD immediately prompts the user to
ENTER SECURITY CODE
.
The
user must input the 4-digit security code to access the calibration menu. This
discourages unauthorized users from accessing and tampering with the calibration
settings. All IEQ Chek™ instruments are shipped from the factory with a generic
security code setting of “1234”. The user can easily change this code setting for extra
security. For additional information on changing the security code, see page 15.
NOTE:
If the wrong security code has been entered, the LCD displays
INVALID
SECURITY CODE ENTERED
and the display returns to the menu list.
The calibration menu provides the user with two main functions to calibrate all gas
sensors: ZERO and SPAN. Both of these functions are required as part of the regular
instrument maintenance to achieve best performance from the sensors.
The zero
function must be performed before the span function.
Below are general guidelines for sensor calibration frequency for best performance.
Sensor Types
Calibration Frequency
Recommendations
Photo Ionization Detection (PID) sensors for Total
Volatile Organic Compounds (TVOCs)
Every 3 months
*
Electrochemical toxic gas sensors
Every 6 months
O
2
sensors (use “clean” ambient environment)
Every 6 months
Infrared CO
2
or combustible gas sensors
Every 12 months
Temperature sensors (at factory)
Every 12 months
Relative humidity sensors (at factory)
Every 12 months
* Depends on exposure amount and duration.
NOTE:
Total Volatile Organic Compound (TVOC) sensors measure the “total”
response from all VOCs in the target area and cannot identify individual gases or
chemicals.
Both zero and span functions are automated. Before span adjusting the sensor, the
user must first tell the IEQ Chek™ what concentration of span gas is being used to
span each sensor. This
does not
apply to temperature, RH, or oxygen sensors.
Temperature and RH sensors must be calibrated using a controlled environment such
as a calibration chamber. With oxygen sensors, it is assumed you will use the
environment around you because it contains approximately 20.9% O
2
.
NOTE:
For more information on the calibration function, see page 19 of this manual.
