Sigma 900 Max Portable Sampler

Why buy Sigma Samplers? watch video 


 Features and Benefits:

5 Goals for Effectiveness and Efficiency

Accuracy—highly accurate measurements keep systems in compliance at all times

Simplicity—easy to operate equipment saves valuable time and effort

Flexibility—extensive product options and features accommodate specific needs

Reliability—robust products with minimal downtime and outstanding customer support

Economy—affordably priced products for the best value for the money

Field Convertible for Compact or

Discrete Sampling

Weighing only 28 pounds (12.7 kg)—with a three-gallon polyethylene bottle installed—the Hach Sigma 900 Max Portable Sampler is designed for accuracy and convenience. Quickly switch between composite to discrete sampling in the field using an interchangeable compact-

or standard-sized base. Carrying is made easy with flip-up handles. Configurable for single or multiple bottle applications, it is specifically designed for use in 18-inch manholes.

Reliable Peristaltic Pump Technology

The Sigma 900 Max sampler uses a positive displacement peristaltic pump made of corrosion-resistant Delrin® material. Flow is induced by squeezing a flexible 3/8-in. tube (only the tubing is in contact with the liquid). While other peristaltic pumps fail to meet EPA1 criteria for representative intake velocity, Hach samplers produce a 3.3 ft./s velocity at 3 ft. lift in a 3/8-in. ID intake line. The liquid is under pumped-flow from the point of intake until it reaches the sample bottle.

Advanced Liquid Detection Techniques

The non-contact ultrasonic liquid sensing system guarantees volume accuracy and repeatability regardless of changes in head or composition of the waste stream or temperature variations in the sample liquid. Samples are compromised less often when the intake line is thoroughly purged before and after every sample collection. Reduce cross-contamination with a line rinse where the intake is preconditioned with the source liquid prior to collection. In the event that a plugged intake prevents collection, the unit detects the failed attempt and immediately repeats the cycle starting with a high-pressure purge. 

Easy, menu-type programming is made via a large 8-line
by 40-character backlit display. Use the Sigma 900 Max
sampler to monitor and log rainfall, level, flow, velocity, temperature, pH or ORP, conductivity, and dissolved oxygen
with 12 data logging channels. Depending on model, up to
seven external analog signals can also be logged. As many
as 116,000 readings may be recorded. RAM memory is
C automatically allocated as necessary during operation. Flash memory is used to install software enhancements (available

on the Internet), without returning the sampler to the factory.

Unique Constant Time/Variable Volume Sampling

The patented* Constant Time/Variable Volume sampling method varies sample size in proportion to flow rate—flow- weighted samples are captured on the first try. This method closely simulates manual grab samples. Limitations of conventional samplers, such as insufficient sample volumes during low flow periods or truncated sample time during high flow periods, make capturing short-lived, illicit discharges, or significant storm events difficult. The Constant Time/Variable Volume feature takes regularly timed, proportional samples depending on the flow rate— sample volume increases and decreases with the flow, ensuring that representative samples are taken at even intervals throughout the sampling period. 

Customizable Set Points

Use the Sigma 900 Max sampler to collect samples in response to changing levels of selected parameters—set high and low trip points to immediately collect when a parameter exceeds preset limits. Samples may also be taken only when the parameter exceeds these settings. Out-of-limit sample can then be segregated from normal samples to help quickly identify problem sources.

Easy Data Management Software

Powerful and user-friendly software makes it easy to analyze the data and produce presentation-quality reports—report maximums, minimums, totals, and averages for any time period. Or generate customized reports integrating sample collections with flow, level, rainfall, other water quality parameters such as pH, ORP, temperature, conductivity, or dissolved oxygen. 

Three Ways to Download Data

Sampler to DTU to PC—the palm-sized and waterproof Data Transfer Unit (DTU) is faster, easier, and more economical than a laptop computer to get data from up to 20 samplers to the office.

Sampler to Modem to PC—a built-in modem transmits data via cellular phone or telephone right to the office. Automatically “call” the sampler at predetermined times to retrieve data, or retrieve data on demand. Also, alarm conditions may be sent to up to three pagers or a central monitoring computer.

Sampler to PC—link directly to a PC using the standard built-in RS-232 serial port.


Hach Sigma 900 Max Portable Samplers are ideal for NPDES stormwater compliance, stormwater runoff monitoring, pretreatment compliance, CSO studies and monitoring, industrial wastewater discharge, and WWTP process control. 


Sampler Housing:

  • Impact resistant ABS plastic, 3-section construction
  • Double-walled base with 1 in. (2.54 cm) insulation, direct ice contact with bottles
  • Controller Housing
  • High-Impact, injection-molded ABS; submersible, watertight, dust-tight, corrosion, and ice resistant; NEMA 4X, 6


  • General Use: 0 to 49 °C (32 to 120°F)
  • Liquid Crystal Display (LCD): -10 to 70°C (-14 to 158°F)
  • Storage: -40 to 80°C (-40 to 176°F)

Power Requirements:

  • 12 Vdc supplied by optional a/c power converter or battery
  • Average current with pump running: 2.25 amps dc
  • Average current without pump running: 4 mA dc

ac Power Backup:  (Pump Controller Only)

  • Rechargeable 6 amp-hour gel lead acid battery takes over automatically with ac line power failure
  • Integral trickle charger maintains battery as full charge (factory installed option)

Internal Battery:

  • Two 1.5 V dc “C” cells; maintains program logic and real time clock for five years 
  • Graphics Display
  • 8 line x 40 character alphanumeric, back-lit liquid-crystal graphics display
  • Self prompting/menu driven program

User Interface

  • 21 key membrane switch keypad with 4 multiple function soft keys

Data Logging

  • Records program start time and date, sample volume collected, sample volume remaining, stores up to 400 sample collection times/dates, all program entries, operational status including number of minutes or pulses to next sample, bottle number, number of samplers collected, number remaining, sample volume collected, volume remaining, sample identification, and all logged data
  • Up to 200 events logged, including alarm conditions, program run/stop events, etc.

Set Point Sample Trigger

  • When equipped with integral flow meter, pH/temperature/ORP meter, conductivity, and/or DO monitoring options, sampling can be triggered upon an upset condition when field selectable limits are exceeded

Sampling Modes

  • Multiple bottle time, multiple bottle flow, composite time, composite flow, composite multiple bottle time, composite multiple bottle flow, flow with time override, variable interval, start/stop, and level actuation 

Overload Protection

  • 5 amp dc line fuse for pump; 5 amp dc line fuse for ac power converter


  • Tests keypad, RAM, ROM, pump, distributor, liquid sensor, and velocity signal

Program Languages

  • Czech, Danish, English, French, German, Swedish

Program Lock

  • Access code protection prevents tampering


  • Standard and 12 Bottle Base: 50.5 cm x 69.4 cm (10.9 x 27.3 in.)
  • Compact Base: 44.1 x 61 cm (17.4 x 24 in.)
  • Composite Base: 50.28 x 79.75 cm (19.8 x 31.4 in.)


  • Standard and 12 bottle base: 15 kg (35.6 lb.) with (24) 1-L polyethylene bottles. 14.8 kg (32.6 lb.) with 3-gal polyethylene container
  • Compact Base: 12.2 kg (27 lb.) with (24) 575-mL polyethylene bottles. 12.9 kg (28.3 lb.) with 3-gal polyethylene container
  • Composite Base: 15 kg (36 lb.) with (12) 950-mL glass bottles 

EPROM Flash Memory

  • Via RS232; permits embedded software upgrades in the field; requires ac power

Serial Interface

  • RS-232 compatible; allows on-site collection of stored data 


  • 14,400 bps, V.32 bis, V.42, MNP2-4 error correction
  • V 0.42 bis MNP5 data compression
  • MNP10-EC Cellular Protocol, optional cell phone—FCC approved


  • Sends alarm codes to up to three separate pager telephone numbers or to a dc running data analysis software 

Program Delay

  • 1 to 9,999 minutes or external flow pulses in one unit increments
  • Sampler start time/date and time/day of week
  • Sampler start on external 12 Volt or contact closure input 

Sample Bottle Capacity

Standard Base Capacity

  • (24) 1 L polyethylene and/or 350-mL glass bottles
  • (8) 2.3 L polyethylene and/or 1.9 L glass bottles
  • (4) 3.8 L (1 gal) polyethylene and/or (4) 3.8 L (1 gal) glass bottles
  • (2) 3.8 L (1 gal) polyethylene and/or (2) 3.8 L (1 gal) glass bottles
  • 20.8 L (5.5 gal) polyethylene composite container or (1) 15.1 L
    (4 gal) polyethylene composite container or (1) 20 L (6 gal) polyethylene or (1) 10 L (3 gal) polyethylene or (1) 9.5 L (2.5 gal) glass 

Compact Base Capacity

  • (24) 575 mL polyethylene bottles • (8) 950 mL glass bottles
  • 11.4 L (3 gal) polyethylene bottle • 9.5 L (2.5 gal) glass bottle

12 Bottle Base Capacity

  • (12) 950 mL glass bottles
  • 10 L (3 gal) polyethylene bottle • 9.5 L (2.5 gal) glass bottle 

Composite Base Capacity: (1) 22.7 L (6 gal) polyethylene bottle 

Sampling Features

Multiple Programs

  • Stores up to five sampling programs


  • Allows using two samplers in combination where the first sampler at the completion of the program initiates the second

Upset Sampling

  • When equipped with integral flow meter, pH/temperature/ORP, conductivity, and/or DO monitoring options, or triggered from an external control device, sampling can be triggered upon an upset condition when field selectable limits are exceeded; concurrent with normal sampling routine, sample liquid is deposited in designated “Trouble Bottle(s)” 

Status Display

  • Alerts operator to low main battery, low memory battery, plugged intake, jammed distributor arm, sample collected, and purge failure

Automatic Shutdown

  • Multiple Bottle Mode: After complete revolution of distributor arm (unless Continuous Mode is selected)
  • Composite Mode: After preset number of samples have been delivered to composite container, from 1 to 999 samples, or upon full container.

Sample Volume

  • Programmed in one mL increments from 10 to 9,999 mL 

Sample Volume Repeatability

  • ±5% typical

Interval Between Samples

  • Selectable in single increments from 1 to 9,999 flow pulses (momentary contact closure 25 ms or 5 to 12 Vdc pulse; 4-20 mA interface optional),
  • or 1 to 9,999 minutes in one minute increments

Multiplex (Multiple Bottle Mode)

  • Programming allows multiple samples per bottle and/or multiple bottles per sample collection 

Sample Pump and Strainer

Sample Pump

  • High-speed peristaltic, dual roller, with 0.95 ID x 0.16 OD cm. (3/8 ID x 5/8 in. OD) pump tube

Pump Body

  • Impact/corrosion resistant, glass reinforced Delrin®

Vertical Lift

  • 8.23 m (27 ft.) maximum
  • Note: Remote Pump Option recommended for lifts from 6.7 to 10.7 m (22 to 35 ft.)

Sample Transport Velocity

  • 0.61 cm/s (2 ft./s) minimum, at 4.6 m (15 ft.) vertical lift in a 0.95 cm (3/8-in.) ID intake tube

Pump Flow Rate

  • 60 mL/s at 0.91 m (3 ft.) vertical lift in a 0.95 cm (3/8-in.) ID intake line 

Liquid Sensor

  • Non-wetted, non-contact, ultrasonic Intake Purge
  • Air purged automatically before and after each sample; duration automatically compensates for varying intake line lengths

Pump/Controller Housing

  • High impact injection molded ABS; submersible, watertight, dust tight, corrosion and ice resistant; NEMA 4X, 6

Internal Clock

  • Indicates real time and date; 0.007% time base accuracy

Manual Sample

  • Initiates a sample collection independent of program in progress 

Intake Rinse

  • Intake line automatically rinsed with source liquid prior to each sample, from 1 to 3 rinses

Intake Retries

  • Sample collection cycle automatically repeated from 1 to 3 times if sample not obtained on initial attempt

Intake Tubing

  • 9.5 mm (3/8 in.) ID vinyl or 9.5 mm (3/8 in.) ID Teflon® lined polyethylene

Intake Strainers

  • Choice of Teflon® and 316 stainless steel construction, and all 316 stainless steel in standard size, high velocity, and low profile for shallow depth applications 

Factory Installed Options



  • Field selectable to log pH/temperature or ORP independent of sample operation or to control sample collection in response to exceeding low/high setpoints

pH/Temperature Sensor

  • Temperature compensated; impact resistant ABS plastic body
  • Combination electrode with porous Teflon® junction

Measurement Range

  • pH: 0 to 14 pH
  • Temperature: -10 to 105°C (-14 to 221°F)

Operating Temperature

  • -18 to 80°C (0 to 176°F)


  • 1.9 x 15.2 cm (0.75 x 6 in.) with 1.9 cm (0.75 in.) MPT cable end



  • Field selectable to log dissolved oxygen independent of sampler operation or to control sample collection in response to exceeding low/high setpoints

Measurement Method

  • Galvanic 


  • Temperature compensated; impact resistant polypropylene body

Measurement Range :0 to 20 mg/L

Resolution: 0.01 mg/L

Accuracy: ±3% of reading or 0.1 mg/L

Operating Temperature: 0 to 50 °C (32 to 122 °F)

Dimensions: 1.7 x 15.7 cm (0.65 x 6.25 in.) with 1.9 cm (0.75 in.) MPT cable end



  • Field selectable to log conductivity independent of sampler connection or to control sample collection in response to volume exceeding low/high setpoints


  • Temperature compensated; impact resistant polypropylene body

Measurement Range: 0 to 20 mS/cm

Resolution: 0.01 mS/cm or 1 mS/cm 

Accuracy: ±2% of reading or 0.01 ms

Operating Temperature: 0 to 50°C (32 to 122°F)


  • 1.7 x 15.2 cm (0.67 x 6 in.) with 1.9 cm (0.75 in.) MPT cable end



  • Epoxy body with stainless steel diaphragm


  • Polyurethane sensor cable with air vent
  • Length: 7.6 m (25 ft.) standard; 20 m (15.24 ft.) optional

Sensor Dimensions: 2 x 3.8 x 12.7 cm (0.8 x 1.5 x 5 in.)

Maximum Range: 5 psi, 0.063 to 3.5 mm (0.018 to 11.5 ft.) 15 psi, 0.063 m to 10.5 m (0.018 to 34.6 ft.)

Maximum Allowable Level: 3x over pressure

Operating Temperature: 0 to 71°C (32 to 160°F) 

Compensated Temperature Range: 0 to 30°C (32 to 86°F)

Air Intake: Atmospheric pressure reference is desiccant protected



  • Velocity: Doppler Principle Level: Pressure Transducer


  • Polymer body, 316 series stainless steel diaphragm


  • 8-conductor urethane jacketed sensor cable with air vent
  • Length: 7.6 m (25 ft.) standard, 76.2 m (250 ft.) maximum

Sensor Dimension: 12.7 x 3.8 x 2 cm (5 x 1.5 x 0.8 in.)


  • Velocity Accuracy: 2% of reading Zero Stability: <0.015 m/s (0.05 ft./s) Response Time: 4.8 seconds
  • Profile Time: 4.8 seconds
  • Range: -1.52 to 6.1 m/s (-5 to 20 ft./s) Resolution: 0.3 cm/s (0.01 ft./s) 


  • Depth Accuracy:±1.37 mm (0.054 in.) at 0 to 3.35 m (0 to 11 ft.). ±4.09 mm (0.161 in.) at 0 to10.06 m (0 to 33 ft.)
  • Maximum Allowable Level: 3x over pressure
  • Operating Temperature: 0 to 71 °C (32 to 160 °F)
  • Compensated Temperature Range: 0 to 30 °C (32 to 86 °F)
  • Temperature Error: 0.005 to 3.5 m ±0.0022 m/°C (0.018 to 11.5 ft. ±0.004 ft./°F) 0.005 to 10.5 m ±0.006 m/°C (0.018 to 34.6 ft. ±0.012 ft./°F) Maximum error within compensated temperature range per degree of change.
  • Velocity Induced Error on Depth (patent pending): 0 to 3.05 m/s (0 to 10 ft./s) = 0.085% of reading
  • Air Intake: Atmospheric pressure reference is desiccant protected

Rain Gauge Input

  • For use with Hach Sigma Tipping Bucket Rain Gauge
  • The Sampler Program can be initiated upon field selectable rate of rain
  • Sampler records rainfall data
  • Each tip = 0.25 mm (0.01in.) of rain 

Analog Input Channels

  • Up to 3 additional data logging channels record data from external source(s)
  • Field assignable units: -4.0 to +4.0 Vdc and 0 to 20 mA

4-20 mA Output

  • Up to 2 output signals available User assignable
  • Maximum Resistive Load: 600 ohms Output Voltage: 24 Vdc, no load Isolation Voltage:
  • Between flow meter and 4-20 mA output, 2500 Vac
  • Between the two 4-20 mA outputs, 1 500 Vac

Alarm Relays

  • (4) 10 amp/120 Vac or 5 amp/220 Vac form C relays
  • ±0.1% FS error
  • User assignable for any logged internal or external data channel or assignable event 

Engineering Specifications: 

  1. The sampler shall be suitable for the representative collection of toxic and conventional pollutants.
  2. The sampler shall incorporate a high-speed peristaltic pump for collection of the sample liquid.
  3. The sample pump shall produce a minimum intake velocity of 2 feet per second at 15 feet vertical lift in a 3/8-inch ID intake line.
  4. All electromechanical components shall be protected within a totally sealed housing conforming to NEMA 4X and 6 standards for submersible, watertight, dust-tight, and corrosion resistant operation.
  5. The unit shall have interchangeable compact and standard bases.
  6. The sampler base shall be double wall insulated constructed of beige ABS plastic.
  7. The sampler shall be convertible to discrete operation by installing a modular distribution assembly and bottle set.
  8. The sampler shall be convertible to composite operation by installing a composite container
  9. The controller shall have a hermetically sealed 19 key, multiple function keypad and self-prompting 8 line x 40 character back-lit liquid crystal graphics display.
  10. The sampler shall allow for the following integral options: level meter, flow meter, pH-temperature/ORP meter, temperature meter, dissolved oxygen meter, conductivity meter, rain gauge input, and three (3) analog inputs.
  11. The unit shall have the capability of retaining up to five complete sampling programs in memory.

12. The sampler shall be capable of operation in a timed or flow proportional mode.

13. The sampler shall be capable of rinsing the intake line with the source liquid immediately prior to sample collection.

14. In the event that sample liquid is not obtained on the initial attempt, the sampler shall automatically purge and repeat the collection cycle.

15. To permit sampling during work shifts or other specific periods, the sampler shall be programmable for up to twenty-four start/stop intervals.

16. The sampler case shall be of high impact vacuum-formed ABS plastic, 3-section construction.

17. The base(s) shall be insulated, double wall construction.

18. The base shall hold (select: standard base; 32 pounds of ice with the 350 mL glass bottles in place, compact base; 8.5 pounds of ice with the 575 mL polyethylene bottles in place).

19. The sampler shall be provided with a 4-20mA interface allowing flow proportional sampling from an external flow meter analog output.

20. The sampler shall be provided with a liquid level actuator for program initiation based on a rising liquid level.

21. The sampler shall be provided with a full bottle cut off switch.

22. The sampler shall be the Sigma Model 900 Max Portable Sampler, manufactured by Hach Company 




Ordering information: 

8930: Sigma 900 Max Portable Sampler, with controller, center sections, and top cover (complete sampler requires adding a base option)

8975:  Compact Insulated Base

8976:  Standard Insulated Base

8958: 12 Bottle Base

8561: Composite Insulated Base

Bottle Options

6559: 2.5 Gallon Glass, with Teflon-lined cap

1918: 3 Gallon Polyethylene, with cap

6494:  6 Gallon Polyethylene, with cap

1502: Container Support

8996: Retainer/Full Container Shut-off

737: Set of (24) 1 Liter Polyethylene, with caps

1369: Set of (24) 575 mL Polyethylene, with caps 

2348: Set of (8) 950 mL Glass, with Teflon lined caps 

2217: Set of (4) 1 Gallon Polyethylene, with caps 

2216: Set of (4) 1 Gallon Glass, with Teflon lined caps 

2215: Set of (2) 1 Gallon Polyethylene, with caps 

2214: Set of (2) 1 Gallon Glass, with Teflon lined caps 

Bottle Retainers (for multiple bottles)

2620: Retainer for (12) 950 mL Glass Bottles

2189: Retainer for (24) 350 mL Glass Bottles

1422: Retainer for (8) Glass, (8) Poly, (24) 575 mL Poly, and (24) 1 Liter Poly Bottles

2347: Retainer for (8) 950 mL Glass Bottles 

2190 Retainer for 1 Gallon Glass and 1 Gallon.Polyethylene Bottles


8582: Distributor with Arm for 24 Bottle, Standard Case and 12 Bottle Base

8580: Distributor with Arm for 24 Bottle Compact Base 

8584: Distributor with Arm for 2, 4 and 8 Bottle. Standard Base and 8 Bottle Compact Base 

8583: Distributor Arm only for 24 Bottle Standard Base and 12 Bottle Base, requires distributor assembly 

8581: Distributor Arm for 24 Bottle with Compact Base, requires distributor assembly

8585: Distributor Arm for 2, 4 and 8 Bottle with Standard Base, requires distributor assembly 

Intake Tubing and Strainers

922: 25 ft. Teflon Lined Polyethylene Tubing, 3/8-in. ID (requires Prod. No. 2186 Connection Kit)

2186: Connector Kit, for Teflon lined polyethylene tubing 

920: 25 ft. Vinyl Intake Tubing, 3/8-in ID

2070:  Strainer, all 316 stainless steel

2071:  Strainer, for shallow depth applications, all 316 stainless steel

4652: Strainer, high velocity and shallow dept 

Pump Tubing

4600-15: Pump Tubing, 15 ft. 

8964: Pump Tube Insert 

Integral Water Quality Parameters

8793: Integral pH-Temp/ORP Option, factory installed 

3328: pH-Temperature Probe (grounded), with 25 ft. cable 

3227: DO and Conductivity Receptacle, factory installed 

3216: Kit, D.O. Probe, with 25 ft. Cable

3223: Conductivity Probe only, with 25 ft. cable 

4-20 mA Input

8795: Three (3) Analog Input Data Logging Channels 4-20 mA Output

8797:  First 4-20 mA Output

8798:  Second 4-20 mA Output

Alarm Relays

8984: Four (4) Alarm Relays Modem

1602: Modem, 14,400 baud Rain Gauge

8800: Rain Gauge Receptacle, factory installed Cables and Interfaces

1727: Sampler or Flow Meter to PC Cable 3358 RS-232 Extension Cable


1355: Suspension Harness (suspends the sampler) 

9542: Manhole Support Bracket/Spanner, 18 to 28 in. 

9557: Manhole Support Bracket/Spanner, 28 to 48 in. 

5713000: Manhole Support Bracket, 18 to 27 in.

943: Liquid Level Actuator, 25 ft. cable 

© Hydrotech ZS Consulting 2012