35
087-0020 REV
E
Step 3 –
If spanning the instrument, proceed
to “Span Calibration
STEP
2”
. Observe the LCD indicates the “IHB” function is deactivated
(the transmitter will automatically deactivate inhibit mode after
9 minutes).
Span Calibration
When calibrating the transmitter span, the concentration of the span gas standard
should be at least 20% (BUT NOT IN EXCESS OF 100%) of the transmitter’s range. In
addition, if the calibration gas is not in an air balance (nitrogen for example), do not allow
the gas to flow across the sensor for more than 10 minutes. This will deplete oxygen in
the sensor and cause erroneous readings and slow recovery to normal operation. Most
sensors require a minimum of 5% oxygen for proper operation. Rock Solid sensors do
not require oxygen.
Span Calibration Procedure
To span the Series 5000 Transmitter proceed as follows:
STEP
I -
Inhibit the 4-20 mA output by momentarily placing the
magnet over the “
Z”
(ZERO) calibration zone.
Observe the LCD indicates the “IHB” function is active. (figure)
If using any filter be sure that it is in place prior to applying gas.
Caution:
Avoid placing the magnet over or near the
“Z”
(ZERO) calibration
zone again until after Step 5 or the unit may be taken out of inhibit.
STEP 2 -
Verify that the span gas being used has not exceeded its
expiration date. Old, cold or improperly stored calibration gases (extreme heat
or cold) can degrade causing inaccurate calibration. A minimum gas
concentration of 20% of the full scale range is required; however, a gas
concentration of a least 50% of the full scale range is recommended (BUT NOT
IN EXCESS OF 100%).
STEP 3
- Assemble the specific calibration kit to be used (i.e., permeation tube device,
bottled gas, gas generator, etc.), and make the appropriate connections to the
transmitter’s calibration adaptor. Attach the calibration adaptor to the
transmitter’s sensor, typically p/n 096-2101 (see figure). The 096-2101
attaches to the end cap of the Freedom
™
5000 via a ¼ turn fitting. Verify that
the white diffuser is in place and that the barb fitting is clean of any debris. If
calibrating a sample draw system it is recommended to apply the calibration
gas at the sample inlet. The sample draw system must be allowed to draw the
gas required, typically 500 cc/min. An overflow tee is used for this purpose.
Contact Scott Safety for more information on this overflow tee.
STEP 4-
Initiate gas flow and allow the span gas to flow for approximately 3 to 5 minutes
at a rate of 500 cc/min.
NOTE:
When calibrating outdoors on a windy day, it may be necessary to
temporarily cover the holes around the circumference of the calibration
adaptor. Otherwise, rapid air flow caused by wind will dilute the gas standard
as it enters the sensor area. The holes need not be tightly sealed.
! Tubing Alert !
Ensure the proper
tubing is used when
performing span
calibration. Teflon
tubing should be
used when
calibrating “sticky
gases such as NH3,
Cl2 or acid gases.
! IMPORTANT
If using the
Transmitter with a
Scott Safety filter,
e.g., H2S
Or IPA Scrubber, the
scrubber MUST
be in place prior
to calibration.
Freedom 5000 Universal Analog Toxic Gas Detector
Instruction Manual