120-00012
GasD 8000 Series User Manual
12/14/2020
21
Section 6 - Calibration
Periodic calibration of the GasD
8000 series portable analyzer is required to compensate
for decreased sensor sensitivity and to maintain accuracy of readings. All instruments are
factory calibrated prior to shipment. No calibration is necessary until after considerable use.
The frequency of calibration is a function of instrument use and the concentrations of
sample gas to which the sensor is exposed. As such, no exact schedule of calibration can
be recommended but a good rule of thumb is to calibrate quarterly with regular use.
There are 2 calibration methodologies available which are detailed in the following sections.
The factory recommended procedure for calibrating all INTERSCAN analyzers is the
introduction of a certified calibration gas standard taken from a gas cylinder or a permeation
device. Besides being essential for calibration, having a known certified gas standard on
hand allows the user to test the analyzer at any time to confirm proper functionality.
Whatever the source of calibration gas, the recommended delivery method is via a proper
sample bag which is attached to the analyzer INLET. The calibration gas is drawn from
the proper sample bag through the sensor.
USE AT LEAST A 2 LITER BAG TO ENSURE
ADEQUATE CAL GAS SAMPLE VOLUME.
Teflon® or Tedlar® bags are suitable for H
2
S, SO
2
, NO and NO
2
. Several bag materials
are suitable for CO. Gases that are easily chemisorbed (Cl
2
, Hydrazine etc.) may require
a different method of delivery. Contact the Interscan Factory for recommendations.
Alternatively, a regulated pressurized certified gas cylinder fitted with a tee-manifold and
unrestricted vent is a viable source of calibration gas.
NOTE:
PRESSURIZED SAMPLE MUST BE REGULATED TO 4 PSI OR LOWER.
OVER-PRESSURIZATION CAN DAMAGE THE SENSOR AND VOID THE
WARRANTY!
6.1 GAS CALIBRATION
