Automatic Duckbill Sampler

Duckbill Sampler

The Markland Advantage:

Automate sampling

  • Eliminate the need for staff to manually sample.

Reduce maintenance costs

  • No pump and no vacuum system mean trouble-free sampling.

Move samples up high lifts and over long runs

  • Use compressed air to move the samples, enabling lifts of over 60 ft vertically (18 m) and 100 ft horizontally (30 m).

Install simply and easily, at a remote location

  • Requires only an air-line, running from sampler to the electronic controller.

Sample in potentially hazardous areas, such as Class 1

  • Inherently explosion-proof (no pumps to extract samples); electronic controller can be located far from sample site.

Sample in freezing temperatures

  • Lines are blown dry after every sample.

Maintain compliance with environmental regulations

  • Simple and versatile device facilitates regular sampling, making compliance easier.

Get answers when you have questions

  • Technical assistance direct from the designers and manufacturers of this automatic water and wastewater sampling equipment.


The Markland Automatic Duckbill Sampler is ideal for use in

  • Municipal & Industrial Water and Wastewater Treatment
  • Food, Mineral and Chemical Processing
  • Power Plants
  • Petrochemical, Pharmaceutical & Manufacturing Industries
  • Pulp and Paper Industry
  • Sewers
  • Tanks
  • Open Channels
  • Sumps
  • Reservoirs
  • Lakes and Rivers (Watersheds)


  • virtually no moving parts means reliable, trouble-free sampling; no pump or vacuum system to maintain
  • non-clogging and requires little cleaning
  • unique, simple composite sampler
  • rubber Duckbill stops large particles from clogging the tubes (each time a sample is taken, the Duckbill closes down and expels any large particles, in a self-cleaning action)
  • lines are blown clear and dry after sample is taken, preventing freezing in cold climates
  • controller can start a sample based on time or by a flow meter
  • manual samples can be ‘called in’ at any time without affecting the normal sampling interval
  • controller can drive two sampling heads simultaneously, from two or more locations, simplifying installation and reducing costs
  • sampler head is available in aluminium, stainless steel, and PVC material (for different pH levels)
  • modular design (components can be selected and assembled to suit your specific sampling requirements)

How it Works

Compressed air introduced into the top fitting forces the sample out of the bottom fitting into a collecting bottle. The rubber Duckbill acts like a check valve and prevents air from escaping back through inlet. When the top fitting is vented to the atmosphere, hydrostatic pressure within the liquid bath forces a fresh sample up the vertical inlet and through the Duckbill’s slit until the body is filled above the vent fitting, but below top of the Duckbill. A trapped air pocket in the dome keeps the sampler from filling completely. The sampler is now ready for a burst of compressed air to ‘call in’ another sample to the collecting station. Reverse leakage of the sample back through the Duckbill is impossible. Plant compressed air supply is not necessary. We manufacture a wide range of automatic controls for 110 volt 60 Hz and 220 volts 50 Hz for clock sampling or flow proportional applications. We can supply your complete sampling system, including tubing and fittings, sample collecting bottles, small air compressors, regulators, etc. – everything you need to monitor your process or effluent. Flow Proportional Flow Proportional Industrial SamplingWith the two external control terminals jumpered, a dial sets the time between samples. With the jumper removed and an external normally open (N.O.) contact connected, momentary closures cause one sample to be extracted for every closure. This gives samples proportional to flow when connected to a Flow Meter Totalizer Integrator Switch. In addition, maintaining external contact closed turns the sampler clock ON, and the clock continues to run and extract samples at time interval set on dial until maintained closure is broken. Remote Composite SamplingRemote Start-up When connected to a 24-hour timer, delayed start-up or intermittent operation can be accomplished. If connected to a Float Switch, the sampler can be turned on when liquid level rises, for example sampling storm water runoff. When connected to pH or other type meter, samples can be extracted only when a pollution parameter is out of limits. Remote start-up by radio or telephone signals is another possibility for this multipurpose controller. Sampler Head Explosion-proof sampling head Controller Water and Wastewater Sampling Control


This animated illustration demonstrates how the sampler works. Wastewater equipment to sample influent and effluent  

Technical Specifications

Body Diameter • 73 mm. (2-7/8″)
Overall Height • 127 mm. (5″)
Mounting Lug • Projects 16 mm. (5/8″) • Drilled two 7 mm. (9/32″) holes, 51 mm (2″) on centres
Sample Size per ‘Shot’ (Standard) • 75 ml. (2 1/2 Oz.) • 50 samples = 1 U.S. Gallon
Duckbill Elastomers • E.P.T. (Ethlyene Propylene Terpolymer), standard• Buna-N (Nitrile), use only for oily wastes • Viton (Flourocarbon), special order & extra charge
Materials: Model RS-200-ALUM •Aluminum Alloy, Brass Trim, standard Model RS-200-SS •Type 316 Stainless Steel, all wetted parts. Model RS-200-PVC •PVC Body, plastic tube fittings
*PVC Remote Sampler is available to take 200, 300, 400, or 500 ml. per ‘shot’. Contact us for other sizes.
To receive a quote for a Markland Automatic Duckbill Sampler, please complete the form found below. The more technical details we receive from you, the better will be our recommendation.
Contact Information

State/Prov: Country:

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Your Requirements

Raw SewageSecondary SewagePlant EffluentPulp/Paper Mill EffluentSea WaterFresh WaterOther:
pH: Range from: to with an average of:
Liquid depth at sampling point: cminches
Suspended solids concentration: Average: ppm Maximum ppm
Temperature of liquid: Maximum: °C°F
Type of Solids:
StringyGranularChipsSolids Float
Heavier than water? YesNo
Any other description of solids:
Name any predominant chemicals in the liquid:
Pre-set SamplingFlow Proportional*
* Flow proportional samplers operate from pulse signals received from your flow recording instrumentation.

Daily volume of sampling: Litres per 24 hours
Is power available? YesNo
Volts: Phase: Cycles:
Is compressed air available at the sampling location? YesNo
Height of sample lift: cminches
Horizontal distance sample will travel: metresfeet

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