The Gastec 191TP Acrylonitrile Detector Tubes are designed for quantitative measurement of acrylonitrile (CH2) in air using a compatible automatic air sampling pump.

The 191TP provides an overall quantitative measuring range of 0.2 to 12.6 ppm using two sampling rates. The primary range of 0.2 to 3.0 ppm is measured at 100 mL/min, while concentrations from 3.0 to 12.6 ppm can be measured at 50 mL/min using a ×4.2 correction factor.

The detector system produces a yellow-to-pink color change and has a detection limit of 0.03 ppm under the specified 1,000 mL sampling conditions.

IMPORTANT: The Gastec 191TP uses two connected tubes for each measurement. Each box contains 10 tubes for a total of 5 tests.

Automatic Air Sampling Pump Required

IMPORTANT: Gastec 191TP Acrylonitrile Detector Tubes require a compatible automatic air sampling pump capable of maintaining the specified continuous sampling rates.

Automatic Sampling Pump:
Gastec GSP-501FT Automatic Air Sampling Pump

The Gastec 191TP is an automatic air sampling pump detector tube and should not be treated as a standard hand-pump detector tube.

For the primary measuring range, sampling is performed at 100 mL/min for 10 minutes.

For concentrations above 3.0 ppm, prepare a fresh connected tube set and sample at 50 mL/min for 10 minutes, then multiply the detector tube reading by the specified ×4.2 correction factor.

Do not substitute a standard manual Gastec detector tube pump for the required automatic sampling method.

Measurement & Sampling Specifications

Measurement Range	Sampling Rate	Sample Volume	Correction Factor	Sampling Time
0.2–3.0 ppm	100 mL/min	1,000 mL	1	10 Minutes
3.0–12.6 ppm	50 mL/min	500 mL	4.2	10 Minutes

For measurements from 0.2 to 3.0 ppm, sample at 100 mL/min for 10 minutes, producing a total sample volume of 1,000 mL.

For measurements above 3.0 ppm and up to 12.6 ppm, prepare a fresh connected tube set and sample at 50 mL/min for 10 minutes, producing a total sample volume of 500 mL. Multiply the detector tube reading by 4.2.

Product Specifications

Brand: Gastec
Tube Type: Acrylonitrile Detector Tube for Automatic Air Sampling Pump
Part Number: 191TP
Gas/Vapor Measured: Acrylonitrile
Chemical Formula: CH2
Measurement Range: 0.2–12.6 ppm
Primary Measurement Range: 0.2–3.0 ppm
Extended Measurement Range: 3.0–12.6 ppm
Detection Limit: 0.03 ppm at 1,000 mL (minimum detectable concentration; not part of the quantitative measuring range)
Primary Sampling Rate: 100 mL/min
Extended Sampling Rate: 50 mL/min
Primary Sample Volume: 1,000 mL
Extended Sample Volume: 500 mL
Correction Factor: 1 or 4.2 depending on measurement range
Sampling Time: 10 Minutes
Color Change: Yellow → Pink
Operating Temperature: 5–40°C (41–104°F), temperature correction required
Operating Humidity: 10–90% RH, humidity correction not required
Relative Standard Deviation: 10% for 0.2–1.0 ppm; 5% for 1.0–3.0 ppm
Quantity: 10 Tubes
Tests per Box: 5 Tests
Shelf Life: 24 Months
Pump Requirement: Compatible Automatic Air Sampling Pump Required

Two-Tube Measurement System

The Gastec 191TP requires two tubes to be connected together during each measurement.

Prepare the primary and analyzer tubes according to Gastec's instructions, break the required tube ends, and connect the designated ends using the supplied rubber tubing.

Insert the analyzer tube securely into the automatic air sampling pump with the arrow pointing toward the pump.

Because two tubes are consumed during each measurement, one box containing 10 tubes provides 5 complete tests.

Always follow the official Gastec 191TP instruction manual for proper tube preparation, connection, orientation, and sampling procedure.

Acrylonitrile Measurement

The Gastec 191TP provides quantitative measurement of acrylonitrile concentrations from 0.2 to 12.6 ppm.

The 0.03 ppm detection limit represents the minimum concentration capable of producing a detectable reaction under the specified 1,000 mL sampling conditions. It is not part of the quantitative measuring range and should not be interpreted as a 0.03–12.6 ppm measuring range.

Acrylonitrile reacts with an oxidizing agent to form an intermediate material that stains the detector indicator pink, producing the visible yellow-to-pink color change.

Common Applications

Gastec 191TP Acrylonitrile Detector Tubes may be used for applicable acrylonitrile air-monitoring applications including:

• Industrial Hygiene & Occupational Exposure Monitoring

• Workplace Acrylonitrile Monitoring

• Chemical Manufacturing & Processing

• Plastics, Resin & Polymer Manufacturing

• Synthetic Fiber & Rubber Manufacturing

• Industrial Process Air Monitoring

• Chemical Handling & Storage Areas

• Environmental Atmospheric Monitoring

• Leak & Release Investigations

• Laboratory & Research Applications

Temperature Correction

The Gastec 191TP is designed for use between 5 and 40°C (41–104°F) and temperature correction is required.

Gastec specifies the following temperature correction factors:

Temperature	Correction Factor
5°C (41°F)	4.25
10°C (50°F)	2.25
15°C (59°F)	1.45
20°C (68°F)	1.00
25°C (77°F)	0.85
30°C (86°F)	0.65
35°C (95°F)	0.55
40°C (104°F)	0.45

Multiply the detector tube reading by the applicable temperature correction factor according to Gastec's instructions.

No humidity correction is required within the specified 10–90% RH operating range.

Atmospheric-pressure correction may also be required according to Gastec's official measurement procedure.

Possible Interferences

Certain coexisting substances may affect Gastec 191TP measurements.

Hydrogen Chloride: At 5 ppm or less, Gastec identifies no interference. Hydrogen chloride itself may produce a pink color at concentrations of 10 ppm or greater.

Hydrogen Cyanide: May produce a positive interference and independently produce a pink color.

Acetone: At concentrations of 10 ppm or greater, may produce a positive interference without independently changing color.

Acetone Cyanohydrin: May produce a positive interference and independently produce a pink color.

Ethyl Acetate: At concentrations of 30 ppm or greater, may produce a positive interference. Ethyl acetate itself may produce a pink color at concentrations of 200 ppm or greater.

Toluene: At concentrations of 0.2 ppm or greater, may produce a negative interference. Toluene itself may produce a pink color at concentrations of 70 ppm or greater.

Hexane: At concentrations of 40 ppm or less, Gastec identifies no interference and no independent color change.

Methanol: At concentrations of 40 ppm or greater, may produce a negative interference without independently changing color.

Coexisting gases and vapors should always be considered when interpreting detector tube measurements.

Important

A compatible automatic air sampling pump capable of maintaining both 100 mL/min and 50 mL/min is required for correct use of the Gastec 191TP Acrylonitrile Detector Tubes.

Automatic Sampling Pump:
Gastec GSP-501FT Automatic Air Sampling Pump

For the primary 0.2–3.0 ppm range, sample at 100 mL/min for 10 minutes, producing a total sample volume of 1,000 mL.

For the extended 3.0–12.6 ppm range, prepare a fresh connected tube set and sample at 50 mL/min for 10 minutes, producing a total sample volume of 500 mL. Multiply the reading by the ×4.2 correction factor.

Two detector tubes are required for each measurement. Therefore, 10 tubes provide 5 complete tests.

Do not use a standard manual detector tube pump in place of the required automatic sampling method.

Temperature and atmospheric-pressure corrections should be applied when required according to Gastec's official instructions.

Always follow Gastec's official instructions for tube preparation and connection, sampling rate, sample volume, sampling time, correction factors, environmental conditions, possible interferences, and interpretation of results.

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