18
Gilian
®
LAB & FIELD CALIBRATOR SYSTEM
Sensidyne Document No. F-PRO-1260 (Rev C)
3.3.2
Low Flow Control System Calibrations
This procedure applies to HFS-113 & HFS-513 sam-
plers with low flow capability and GilAir/GilAir-5 sam-
plers with Multi-Flow Modules in the “On” Position.
The suction/pressure regulator in conjunction with a
manifold provides the means for setting low flow
To determine or check these pressures, set sampler
flow rate, (between 1–1.5 LPM), blocking the pump in-
let and setting a back pressure of 20–21” H
2
O for HFS-
113 & HFS-513 pumps and 16” H
2
O for GilAir/GilAir-5
pumps, indication on the pressure gauge.
In this set up, the pump is connected to inlet (B4) and
the Load Selector Valve (V1) is set to “Bypass”.
Block the Air Inlet Fitting (B1). The flow rate will drop
to zero and the pressure gauge will peg at 20-21” H
2
O.
This can also be accomplished by closing (clockwise)
either the “High Flow Adjust” (V3) or “Low Flow Ad-
just” (V4) and then positioning the “Load Selector
Valve” to either position.
The GilAir with a constant-pressure module can be
checked in the same manner except there is no adjust-
ment for the suction/pressure, only verification.
The suction/pressure should be greater than 16” H
2
O.
To determine the stability of the regulator in all of the
above cases, set the Load Selector Valve (V1) to “By-
pass”, shut the Low Flow Adjust Valve (V4) by turning
fully clockwise, then set the Flowmeter Selector Valve
(V2) to the High flow range flowtube and connect the
sampler to the Air Inlet Fitting (B1).
Turn sampler ON and adjust the flow to 1 LPM HFS-113
& GilAir and 1.5 LPM for the HFS-513.
Turn the load selector valve to the “Low Flow Adjust”
position (V4). Be sure valve is shut off.
The regulator should go up to approximately 20-21”
H
2
O for HFS-113, 24-25” H
2
O for HFS-513 and a mini-
mum of 16” H
2
O for GilAir. If the pressures are out of
specifications, the pump should be leak checked and
the “Low Flow Adjust” reset to apply the proper pres-
sure range.
NOTE
It is imperative that flow rates are in the approximate
range, and flowtubes must be calibrated to determine
this.
