M18A2 Chemical Agent Detector Kit

The M 18A2 chemical agent detector kit (fig. 9-6) is used to detect dangerous concentrations of toxic chemical agents in the atmosphere as well as residual surface contamination. The agents that may be detected by this kit are AC, CG, CK, CX, ED, G, H, HD, HN, L, and V. If a toxic agent is suspected but cannot be identified, collect samples of the agent and forward them to an appropriate laboratory for identification. The M18A2 detector kit consists of an aspirator bulb assembly, detector tickets, detector sampling tubes, reagent packets, a substrate dispenser, M-8 detector paper, and some other accessories.

Before using the detector kit, check the detector tickets in the belt as described below. Make this initial check just before each entry to a contaminated area to ensure that the belt is serviceable. All of the tickets used for the initial

Figure 9-7.-Checking detector ticket before use.

Figure 9-8.-Preparing ticket for use. 9-20

check should be discarded since the ability of these tickets to detect agents may be destroyed. The following procedure for checking detector tickets may differ from that given in the detector instruction cards. However, this procedure is preferred. When reading the following discussion on the initial check procedures, refer to figure 9-7.

1. Detach a plastic envelope containing a detector ticket from the belt of tickets.

2. Tear the envelope approximately one-half inch from the top of the round end of the ticket (view A). The existing notch or small slash in the envelope will assist in making this tear.

3. Push the round end of the ticket out of the envelope (view B).

4. Add two drops of reagent from the whitemarked bottle onto the disk (view C). If the disk does not wet easily, insert the ticket into the envelope and massage the round end of the ticket in the envelope until the disk is uniformly wet.

5. Remove the plastic guard from the redmarked substrate dispenser. Push the round end of the ticket out of the envelope if it has been placed back in the envelope. Carefully add two drops of the substrate solution onto the wet disk (view C). If the disk does not turn blue within

3 minutes, insert the ticket into the envelope and massage the ticket. If a blue color does not develop, discard the ticket and obtain a fresh one.

Once the initial check is completed and the belt of tickets has been determined to be serviceable, you will need to prepare the detector ticket for use. This can be done just before you go into a contaminated area, or while you are in a contaminated area. Refer to figure 9-8 as you read the discussion on preparing a detector ticket for use.

1. Detach a plastic envelope containing a detector ticket from the belt of tickets.

2. Tear the envelope approximately one-half inch from the top of the round end of the ticket. The existing notch or small slash in the envelope will assist in this tear.

3. Reverse the ticket in the envelope until the square end is out of the envelope (view A).

4. Place two drops of reagent from the whitemarked bottle onto the disk in the square end (view B). If the disk does not wet easily, reinsert the ticket into the envelope and massage the square end of the ticket until the disk is uniformly wet.

Now you are ready to collect and test vapor samples for chemical agents. Refer to figure 9-9

Figure 9-9.-Collecting and testing vapor samples for V or G agents. 9-21

as you read the following discussion on the collection and testing of vapor samples. Use the following procedures while conducting these tests:

1. Install the square end of a prepared detector ticket in the aspirator bulb adapter with the plastic cross support behind the disk facing toward the bulb (view A).

2. Direct the ticket toward the ground (view B) and compress the bulb 60 times. Allow the bulb to reinflate completely between compressions.

3. Withdraw the ticket from the aspirator bulb adapter and insert the round end of the ticket into the envelope (view C) so that the square end is not covered by the plastic.

4. Carefully add 2 drops of substrate solution onto the disk at the square end of the ticket (view D). Push the ticket all the way into the envelope. Massage the ticket in the envelope.

5. Observe the color of the disk in the square end of the detector ticket. Indication will appear within 3 minutes.

a. If the disk is white or light red-orange, there are V or G agents or a combination of V and G agents in the atmosphere.

b. If the disk is blue, there are no V or G agents present.

c. If most of the disk is white or light redorange with a fringe of blue, there are very low concentrations of V or G agents.

To test for CK agents, use the following procedures:

1. Snap both ends from a blue-band detector tube at the scorings. Press the unmarked end of the detector tube into the adapter. With the detector tube pointing down, compress the bulb 60 times.

2. Remove the detector tube from the adapter. If a yellow or orange color appears in the detector tube, CK is present. If a CK agent is present, discard the detector tube and omit the test for G agents and the test for mustards or CS.

To test for G agents, use the following procedures:

1. Perform this test only if the CK test is negative (no yellow color) following the detector ticket test. Use the blue-band detector tube from the CK test for this test. White-band detector tubes may be used if there is a shortage of blueband tubes. However, the white-band detector tubes are NOT to be used to test for other than G agents.

2. Squeeze 1 drop of reagent solution from the green-marked bottle into the banded end of the detector tube. If yellow appears within 1 minute, G agent is present.

To test for mustard or CX vapors, use the following procedures:

1. Perform this test only if the CK test is negative. Use a blue-band detector tube for this test.

2. Snap both ends from the detector tube at the scorings. Press the unmarked end of the tube into the adapter. With the detector tube pointing down, compress the bulb 60 times. Remove the detector tube from the adapter.

3. Wait at least 2 minutes after sampling, then squeeze 1 drop of reagent solution from the bluemarked bottle into the banded end of the detector tube.

4. If the purple-blue ring or color appears, H, HD, HN, or HT is present. If a red-brown ring or color appears, CX is present. (A light-brown color that fades within 15 seconds is not a positive test.)

To test for L, ED, or MD agents, use the following procedures:

1. Use a yellow-band detector tube for this test. Snap both ends from the detector tube at the scorings. Press the unmarked end of the detector tube into the adapter. With the detector tube pointing down, compress the bulb 60 times.

2. Remove the detector tube from the adapter and observe the color. If a blue-green ring or color is observed, ED or a high concentration of L is present.

3. Squeeze 1 drop of reagent solution from the blue-marked bottle into the banded end of the detector tube. If a blue or blue-green ring or color appears, L, ED, or MD (singly or in combination) is present.

To test for CG agents, use the following procedures:

1. Snap both ends from a green-band detector tube at the scorings. Press the unmarked end of the tube into the adapter. With the detector tube pointing down, compress the bulb 60 times.

2. Remove the detector tube from the adapter and observe the color. If a green ring or color appears, CG is present.

To test for AC agents, use the following procedures:

1. Snap both ends from a red-band detector tube at the scorings. Press the unmarked end of the detector tube into the adapter. With the detector tube pointing down, compress the bulb 60 times.

2. Remove the detector tube from the adapter. If a blue ring or color appears in the detector tube, AC is present.

To test for liquid agents (blister and nerve agents) on surfaces, use the M-8 detector paper that is supplied with the kit. Follow the procedures that were discussed earlier when you use the M-8 detector paper.

You may not get a positive reading from the above tests. If this happens and you still suspect that a chemical agent is present, use the following procedures to conduct further checks:

1. Complete a report card. Be sure to record information that may be helpful in determining the nature of the unknown agent. Describe the unit taking the samples; the place, date, and time the samples are taken; observed characteristics of the agent; and the effect of the agent on personnel. List the observed color effects on the various types of detector tubes.

2. Select an area for sampling that is likely to have a high concentration of agent (a depression in the ground or just above a

puddle of liquid agent). Take samples in five white-band sampling tubes. The instructions given below apply to each of the five sampling tubes.

a. Snap both ends from a white-band sampling tube at the scoring. Press the unmarked end into the adapter.

b. With the sampling tube pointing down, compress the bulb 60 times.

c. Remove the sampling tube from the adapter and place it in the envelope containing the completed record card.

3. Place the five sampling tubes and the report card in an envelope, seal the envelope, and forward it to the chemical laboratory designated.

The following steps should be used to keep the M18A2 detector kit in a usable condition.

1. Keep the kit dry because it is not waterproof.

2. Inspect the kit for worn or unusable parts. Replace those parts as necessary.

3. Examine the red-band and green-band detector tubes (without regard to detector kit discard date) to determine if they are in usable condition.

a. A red-band tube is in usable condition when the impregnated silica gel is colorless or light pink. Discard red-band tubes when the impregnated silica gel is blue or green. (See instruction cards for color.)

b. A green-band tube is in usable condition when the impregnated silica gel is yellow or light tan. Discard green-band tubes when the impregnated silica gel is brown or green. (See instruction cards for color.)

4. Check the aspirator bulb at least semiannually. Insert the end of a sealed detector tube (end broken) in the aspirator bulb adapter. Compress the bulb, holding the valve end up. The bulb should require at least 10 seconds to reinflate after the bulb has been released. If the bulb reinflates in less than 10 seconds, it leaks.

Figure 9-10.-Chemical warfare directional detector (CWDD) and stowage case.