- The sampler shall be suitable for automatic collection
and preservation of composite or discrete non-toxic liquid samples.
- The sampler enclosure shall be thick walled ABS
with NEMA 4X/NEMA 6 ratings.
- Minimum ID of all wetted parts is 3/8-inch. Non-toxic
samples shall be collected using a clear PVC measuring chamber adjustable
10 to 500 ml sample volume and ±0.5% repeatability of preset
value. All wetted parts are stainless steel, PVC, or silicone rubber.
- The sampler incorporates vacuum compressor technology.
The sampling mechanism consists of a heavy-duty vacuum compressor
with an aluminum body coated with corrosion-resistant paint. The
sample does not pass through a pump. Samplers using technologies
requiring regularly scheduled parts replacement will not be acceptable.
A 500 ml precision measuring chamber with ± 0.5% repeatability
of preset volume is used. Determining sample volume using contacting
electrical probes or by inferentially deriving volume through measuring
flow based on pump rotations or time is not permissible. There is
no need to compensate for changes in draw height or intake line
length.
- The sampler enables field conversion from multiple
to single bottle sampling to collect non-toxic liquids by using
a parts kit which does not require special tools.
- Composite and/or discrete samples are collected
by the sampler. For composite sampling, an overflow protection mechanism
shall automatically terminate any further sampling. Discrete sampling
can be multiple bottles of the same sample or multiple samples in
multiple bottles. Systems relying upon sensing bottle weight to
determine sample volume is unacceptable due to the variance in sample
densities and the need to calibrate the weight sensing mechanism.
- Bottle-full condition is detected using a stainless
steel sensor located in the bottle neck. It is easily removable
for cleaning or replacement without using special tools.
- The sampler is capable of collecting 10 to 2000
ml samples through a 3/8-inch ID sample line at a minimum transport
velocity of 2.5 ft./sec. at 20 feet of lift using a 25 ft. long
sampling hose, and a 7 ft./sec. At 3 ft. of lift using a 15 ft.
long hose.
- An optional weighted sampling strainer of PVC
or stainless steel is used.
- A hermetically sealed 24-button keypad and a 2-line
by 20-character alphanumeric backlit LCD is linked to a programmable
CPU.
- Sample bottle(s) are located below the controller
in a carbon steel refrigerator (with iron phosphate pretreatment
covered by baked acrylic enamel or a stainless steel refrigerator.
The refrigerator condenser is made of carbon steel with baked enamel
finish. For protection from hydrogen sulfide gas attack, copper
refrigerant lines are coated with asphalt cork tape. A thermostat
is included within the refrigerator to ensure that a temperature
of 4OC is maintained. The evaporator coils are rolled aluminum with
baked acrylic enamel finish. The fan motor is unit bearing. The
475 BTU compressor has a high efficiency fan and condenser arrangement
permitting reliable operation in high ambient temperatures. Insulation
is foam formed CFC-free polyethylene with an interior of food grade
ABS.
- No unique symbols or codes for programming or to
indicate operating conditions are used. The software, menu driven,
prompts input of requested information by using the keypad. The
display indicates each programming step. After entering date, the
systems automatically advance to the next programming step.
- A password feature is used to restrict access to
authorized persons only.
- A sampling program can be delayed by entering the
time in hours and minutes for the sampler to count down, or the
number of contact closures to occur. The delay is independent of
the sampling interval.
- Immediately prior to and following each sample,
the sampler purges the sample hose. Purge duration is selectable.
- If a sample is not obtained on the first attempt,
the sampler immediately retries to collect the sample. If a sample
still cannot be collected, the sampler will omit that sample and
continue the sampling sequence.
- Manual sampling, independent of a programmed sequence,
is initiated by a keystroke. The sampler logs manual collections
is selectable to allow taking test samples:
- Only when sampler is not running a program.
- During a program but the test sample is not
counted as a sample.
- During a program and the test sample is counted
as a sample.
- In the time mode, the interval between samples
is adjustable (1-9999 min. in 1 min. increments). In the flow mode,
the sampler accepts and totalizes contact closures (1-9999) or a
4-20mA DC analog signal input for sampling at a user set point.
- A hydrologic event algorithm is used to enable
sample programming based on a combination of parameters including
water level, differential (rising and falling) water levels, and
time defaults as established by the U.S. Geological Survey for hydrologic
events.
- Operating status is reviewed with minimal effort
and includes:
- Program status
- Time and date program started
- Minutes or flow signals remaining to the next
sample
- Bottle number
- Number of samples collected
- Number of samples remaining
- Volume collected, and,
- Volume remaining.
All program settings are also reviewed in addition to seeing the
review of the completed program. The sampler has diagnostics for
RAM, ROM, pump, and distributor.
- The entire refrigerated sampler is enclosed in
an optional weather-resistant, NEMA 3R outdoor enclosure made of
fiberglass-reinforced polyester and insulated with 0.75 in. (19.05
mm) thick polyurethane. It is equipped with a full-size gasket-sealed
door with lockable latch, duplex outlet, air vents, and access holes
for the sampling hose. It also includes any or all of the following:
an optional heater with thermostat suitable for sampler operation
to –4°F outside temperature, an optional light and/or optional
fan.
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