Types of Nextteq® Detector Tubes
Understanding the Types of Nextteq Detector Tubes:
All Nextteq® detector tubes fall into one of the five following categories: 
âžž (1)
Standard Short Term Tubes
(NX100 and NX200 Series)
âžž (2) Multi-teq® Tubes (NX300 Series)
âžž (3) Continuous Sampling Tubes (NX500 Series for IAQ)
âžž (4) Compressed Breathing Air (CBA) Tubes (NX800 Series)
âžž (5) Solution Tubes (NX400 Series)
âžž (6) Passive Dosimeter Tubes (NX900 Series)
âžž (7)
Inline Tubes for Ethyl Mercaptan
(NX156P and NX156LP)
Below is the detailed description within each category. After taking a sample, for most all tubes, the concentration can be read by visually looking at the length of stain directly on the tube. For some, a color chart or concentration chart is used for determining the concentration, and for some there are humidity and/or temperature corrections that must be applied to obtain the exact concentration.
All Nextteq® detector tubes come with an instruction sheet which is contained in each box and can also be viewed or downloaded on-line. In addition, all Nextteq detector tubes have a data sheet (a.k.a. handbook page) which contains relevant information for each tube and can be viewed or downloaded on-line. Both the instruction sheet and the data sheet are key pieces of documentation that must be read prior to taking a sample or to obtain an accurate reading.
Warning: To obtain accurate and reliable readings, all Nextteq-branded detector tubes must be used with the NX-1000 Sampling Pump.
âžž (1) Standard Short Term Tubes
(Tubes that are read immediately after a sample is taken)
Required apparatus: the Nextteq® NX-1000 pump
> Short Term - Length of Stain Tubes
Short term – length of stain tubes (NX100 and NX200 series).
Ninety percent of all Nextteq detector tubes fall into this category.
There are 4 scenarios described below in which the concentration is determined by reading the length of stain tube. After determining the concentration, you may need to apply a correction factor for humidity and/or temperature as identified on the tubes instruction sheet to obtain a final reading.
1) Read the concentration directly from the tube for a specific target gas.
2) Read the concentration directly from the tube for a different application – these tubes are identified with an * in the Nextteq Detector Tube Guide or the on-line searchable database and fit into one of the two scenarios:
i. Direct read from the tube for a different application.
• For example: NX202*, a Phenol Tube, is a direct read from the scales printed on the tube but is used to detect Cresol.
ii. Direct read from the tube and use a conversion graph or table obtained from the instruction sheet for a different application.
• For example: NX189*, a Methyl Methacrylate Tube, is a direct read from the scales printed on the tube; however, the reading is converted to detect Allyl Alcohol using a conversion graph or table.
3)
Short term – special concentration chart detector tubes
have no scale
printed on the tubes but length of stain is read using a concentration chart. The concentration chart is obtained in the instruction sheet.
4) Short term – special conversion chart tubes use conversion charts available upon request for special applications at 20°C or 68°F.
(See Table 1 in the Nextteq Gas Detection System Detector Tube Guide.)
NOTE: This chart is applicable for measurements taken at 20°C (68°F) using 3 pump strokes.
> Short Term - Color Chart Tubes
Short term – color chart tubes/color intensity tubes (NX119SA & NX119SB)
–tubes whose reagent sections will show a change in color intensity proportional to the concentration of the target gas using a color intensity chart.
âžž (2) Multi-teq® Tubes
(Tubes that are read after extended period of time)
Required apparatus: A constant flow sampling pump
Multi-teq ™ tubes
(NX300 tube series) --
tubes that have several sections of specific reagent that will change color to identify the type and qualitative concentration of gas present. Two tubes (NX301 and NX302) for Organic and Inorganic gas detection.
âžž (3) Continuous Sampling Tubes
(Tubes that are read over an extended period of time)
Required apparatus: A constant flow sampling pump
>
Continuous Sampling -
Length of Stain Tubes
Continuous Sampling – direct read tubes (NX500 series) require a constant flow pump like the Nextteq NX-300 or NX-1200 – Special high sensitivity tubes for Indoor Air Quality applications. Results are obtained over an extended period of time.
(See
Table 4 in the Nextteq Gas Detection System Detector Tube Guide.)
Nextteq® NX-300
10-300 mL/min
Nextteq® NX-1200
10-1200 mL/min
âžž (4) CBA tubes
(Tubes used for compressed air testing)
Required apparatus: the Nextteq® CBA kit with Nextteq® regulator
>
CBA Tubes -
Length of Stain Tubes
CBA tubes - direct read tubes (NX800 series) are used with a Nextteq Regulator Assembly found in the Nextteq CBA Kit and provide a simple method for detecting contaminants in compressed gas and supplied air.
(See
Table 10
in the Nextteq Gas Detection System Detector Tube Guide.)
âžž (5) Solution Tubes
(Tubes used for testing dissolved substances in liquids)
No apparatus required.
>
Solution Tubes -
Length of Stain Tubes
Dissolved Substances – direct read tubes (NX400 series) that provide economical on-the-spot detection of trace chemicals in liquids.
(See
Table 6 in the Nextteq Gas Detection System Detector Tube Guide.)
âžž (6) Passive Dosimeter Tubes - TWA
(Tubes that are read after extended period of time)
Works with Nextteq Dosi Tube Holder
>
Passive Dosimeter - Length of Stain
Continuous Sampling – direct read dosimeter tubes (NX900 series) – Time Weighted Average (TWA) tubes - Results are obtained over an extended period giving a clear and distinctive line of demarcation.
The Nextteq Dosimeter Tube holders can be used to clip the tube to one's lapel or on a belt. The tube can also be placed in an area and read at a later time.
âžž (7) Inline Tubes for Ethyl Mercaptan
Tubes for testing LP-gas (liquid petroleum gas)
Works with apparatus not sold by Nextteq®
>
Passive Dosimeter - Length of Stain
Inline Detector Tubes for testing LP-gas (NX156P and NX156LP)
These tubes are simple and economical to use. Simply place a tube into the inline sampling point apparatus and allow the gas to flow through the tube. Sampling for ethyl mercaptan is complete in just 1 minute for the NX156P or 3 minutes for the NX156LP. These specialty detector tubes offer advanced technology, providing more accurate and reliable analysis with lower standard deviation. A direct-read scale printed on each tube means faster sampling time with no confusion, dual scales, or concentration charts.
(See
Table 8
in the Nextteq Gas Detection System Detector Tube Guide.)
