​GLS​ Compact Composite Sampler

It’s a great little sampler!

The GLS Sampler is designed for general purpose or priority pollutant sampling in municipal and industrial applications where a full-size sampler is too large. It collects composite samples, based on time or flow intervals, in 1- or 2.5-gallon glass or polyethylene bottles, or in 2-gallon disposable ProPak bags.

With GLS’s simplified programming, setup takes less than a minute. In the field, the operator simply calls up the program with two keystrokes, presses the “go” button – and the sampling routine begins. You can also key in an alternate program in the field, without losing your stored program.



​​​​​​​​​​​​​GLS Sampler
Size (Diam. x Height):16.5 x 26.5 inches (42 x 67 cm)
Weight:24.5 lbs (11.1 kg) (dry, less battery)
Sample bottles:1.0 or 2.5 gallon polyethylene or glass container.
Power Requirements:12 volts DC. (Supplied by battery or AC power converter.)
Intake purge:Purge before and after each sample.
Tubing life indicator:Provides a message to change pump tubing.
Intake suction tubing:Length 3 to 99 ft. (1 to 30 m), Vinyl or Teflon® lined, ID 0.375 in. or 0.250 in
Pump tubing life:2,000 samples
Typical repeatability:±10 ml
Maximum lift:26 ft. (7.9 m)
Typical line velocity @ Head height:2.9 ft./s @ 3 ft; 2.5 ft./s @ 10 ft; 1.9 ft./s @ 15 ft. (0.76 m/s @ 0.9 m; 0.76 m/s @ 3.1 m; 0.58 m/s @ 4.6 m)
Sample presence detector:Non-wetted, non-conductive sensor detects when liquid sample reaches the pump to automatically compensate for changes in head heights.
Operational Temperature:32° to 120°F (0° to 49°C)
Enclosure:NEMA 4X, 6 IP67
Program storage:1 sampling program (in non-volatile ROM)
Flowmeter signal input:5 to 15 volt DC pulse or 25 millisecond contact closure.
Number of composite samples:Up to 500 maximum
Clock accuracy:1 minute per month, typical, for Real Time Clock
Sampling modes:Uniform time, flow. (Flow mode is controlled by external flow meter pulses.)
Sample frequency:1 minute to 9,999 minutes, in 1 minute increments. 1 to 9,999 flow pulses.
Sample volumes:Programmable 10 to 9,990 ml in 1 ml increments
Controller diagnostics:Tests for RAM, ROM, pump, and display

Standard Features

  • Overall diameter is only 16.5 inches (42 cm), so GLS fits easily into manholes as small as 18 inches (46 cm), and also easily drops into most offset manh​oles.
  • Dry weight is less than 25 lbs (12 kg), the lightest sampler in the ISCO line.
  • Hinged handle makes one-handed carrying a breeze.
  • ​The patented LD90 Liquid Presence Detector and ISCO pump revolution counting system deliver accurate, repeatable sample volumes time after time.


  • Wastewater effluent
  • Stormwater monitoring
  • CSO
  • Permit compliance
  • Pretreatment compliance

Options and Accessories

  • Composite Sampling bottle configurations (1-gallon or 2.5 gallon glass or plastic; 2 gallon ProPak disposable sampling system)
  • Power sources
  • Suction lines and strainer​