Uniphos ASP-40 User manual

UNI
AIR
IN
PHOS PRECISION
SAMPLING PUMP
MODEL : ASP
-
40
STRUCTION MANUAL

INSTRUCTION MANUAL FOR UNIPHOS PRECISION AIR SAMPLING PUMP MODEL:
ASP-40
The UNIPHOS precision gas detector consists of two parts viz. i) the gas detector tubes and ii) air
sampling pump (ASP-40). Together they form the UNIPHOS gas detection system. The air
sampling pump is used to draw a precisely defined volume of sample air through the detector tube
for determining the impurity gas concentration in the air sample. This manual describes the air
sampling pump and its operation for impurity gas measurement using detector tubes.
1. DESCRIPTION
ASP-40 is a piston and barrel air-sampling pump (Fig.-1). For measurement, a detector tube with
both ends cut is connected to the rubber tube connector at the end of the barrel.When the piston
is withdrawn by pulling the handle, sample air is drawn into the barrel through the detector tube.
Fig.-1 Uniphos Precision Air Sampling Pump (ASP-40)
Fig.-1 shows the different parts of the air-sampling pump, which are described in the following
section.
1.1 Tip cutter:
The tip cutter is provided on the pump to break off both ends of the detector tube before it is
inserted into the rubber tube connector for drawing the air sample. The broken tips are
collected into a storage space which when filled is to be emptied by pulling off the rubber cap
on the opposite side.

1.2 Vac. Test (Flow indicator):
The Vac. Test is meant for testing the vacuum holding capacity of the air-sampling pump as
well as to see the completion of sampling.
1.3 Stopper:
The air-sampling pump can lock the shaft after pulling and reaching 50 cc (1/2 stroke) or 100
cc (full stroke) mark. For locking, the red dots on the stopper and shaft have to be aligned. In
this position when the shaft is pulled it gets locked at 50 or 100 ccmark. By turning the handle
right or left by 90 degree when in the locked position, the shaft is freed.
1.4 Rubber tube connector:
The rubber tube connector is meant for securely holding the detector tube for drawing
the sampling air.

2. OPERATION
The detector tube system is based on the following working principle. A precisely defined
volume ofsampleair is drawn through the detector tube.The detector tube contains the sensing
chemical, which reacts with the impurity gas in the sample air and produces a coloured stain in
the sensing chemical. The length of the coloured stain measures the impuritygas concentration
in ppm on the tube scale. The measurement involves the following steps.
2.1 Inspect the pump as described in section 3.
2.2 Break both ends of the tube using tip cutter.
2.3 Insert one end of the tube securely in the rubber tube connector ensuring that the arrow
on the detector tube points towards the pump.

2.4 Align the red dots on the stopper and shaft and pull the pump handle to the 50 cc or 100 cc mark.
2.5 Keep the end of the tube in the sample gas source while the gas is being drawn through the tube
for the allotted sampling time (approximately1- 3 minutes) as indicated on the tube sheet. The
sampling is considered to be completed when the white disc in
‘Vac. Test’ indicator returns to its original position.(see Fig.3)

2.6 To draw more than 100 cc, (one stroke) free the handle by rotating it 90 degrees and push back
thepistonshafttoitsoriginalpositionwithoutremovingthedetector tube.Pull thepump handle
again, for the second stroke. These steps can be repeated to get the desired number of
strokes.
2.7 The target gas concentration is directly obtained on the detector tube scale.
3. INSPECTION OF THE PUMP
Before use, the pump should be checked for air leak. The following steps are
recommended.
3.1 Insert a new detector tube without breaking its ends into the rubber tube connector.
3.2 Align the red dots and pull the pump handle a full stroke.
3.3 Wait for three minutes, and release the pump handle by turning 90 degrees on left or
right and slowly allowing the piston to come back by holding the handle.
3.4 If it does not come back completely to its original position it means that there is a leak in
the pump, the cause for which could be one of those described in section 4 under
maintenance.
4. MAINTENANCE
The pump needs occasional maintenance.
4.1 Greasing the barrel and replacing the plunger gasket:

i. Pull the pump handle a little and unscrew the end flange fully.
ii. Pull out completely the piston in the barrel along with the stopper.
iii. Mop up the piston and the inside surface of the barrel. Smear a thin layer of fresh grease
on the rubber packing of the piston.
iv. Inspect the piston gasket on the end of the plunger for damage. To replace the gasket,
use a small screw driver or other sharp tool to pull off the worn gasket, and slip a new
gasket into the groove.
Grease well.
v. Put back the piston in the barrel and tighten the flange.
4.2 Replacement of rubber tube connector:
If the rubber tube connector is worn out, take off the connector holder and replace it with a new
one.

CONNECTOR HOLDER
RUBBER TUBE CONNECTOR
Fig. -10 Rubber tube connector assembly
4.3 Correcting leaking pump:
In case of a leaking pump the following should be checked and if necessary replaced or
corrected.
Symptom
Corrective action
Rubber tube connector is
loose
Rubber tube connector is
worn or damaged
Piston sticks or slip too
easily
One-way valve(s) on the
pump is leaking
Tighten connector holder
Replace the tube connector
(inlet adapter)
Clean and re-grease inside
of barrel and /or replace
piston gasket
Return for service
* * * * * * * * *