Ion Science TVOC - Manual (Page 16)

TVOC MANUAL Ion Science Ltd
Page 16 of 32
Unrivalled Detection. www.ionscience.com
Operation
Start Up
After electrical power is connected, TVOC runs through a ‘Start up’ routine, which lasts for approximately 1
minute. During this ‘Start up’ routine TVOC demonstrates the following characteristics:
* The LCD screen displays the software version number
* The GREEN LED flashes
* The 4-20 mA output is set to 4 mA (0.0 ppm)
NOTE: If the 0-10 ppm range is selected the TVOC will require calibration using 10ppm Isobutylene before
use (See the calibration section of this manual)
During this ‘Start-up’ time the user can adjust the Duty Cycle time as referred to in ‘TVOC Setup’ under the
Duty Cycle section. This time can be adjusted from 0 to 5 minutes in 10 second increments.
Adjusting the Duty Cycle
NOTE: Please read this entire procedure before attempting to adjust the lamp OFF time.
There are two stages to adjusting the Duty Cycle time. The first stage adjusts the seconds 0 to 59 seconds,
the second stage adjusts from 0 to 5 minutes. Please see the description of the Duty Cycle on page 10.
1. During the 1 minute ‘Start up’ time place the calibration magnet over the top
right hand corner of the Ion Science logo. (See diagram 9) Two numbers on the
right of the LCD screen will flash.
Diagram 9
2. While the magnet is held in this position the number on screen will roll over from 00
through to 50 in 10 second steps. Quickly remove the magnet when the desired time
appears.
3. After 5 seconds the TVOC will move on to the next stage. (Reapply the magnet
within 5 seconds if further adjustment is necessary)
4. The TVOC will move to the next stage indicated by a digit appearing on the left of
the screen. Holding the magnet in place will cause this number to roll over from 0 to 5
minutes. Quickly remove the magnet when the desired time appears.
5. After 5 seconds the TVOC will display both the minutes and seconds selected.
(Reapply the magnet within 5 seconds if further adjustment is necessary)
6. TVOC will restart the start-up sequence and then enter running mode. The Duty
cycle is then saved to memory. The duty cycle will be remembered through a power
cycle.
Fast response mode
If the Duty Cycle time is adjusted lower than 0:10 (10 seconds) the instrument will update the output every
one second. In this mode of operation the F2 fault condition is disabled. This means that removal of the
sensor may go undetected.