The Hygrometer,dial Indicating, cataloged under National Stock Number 6685-01-460-5538, is classified within Federal Supply Class 6685 (Pressure, Temperature, and Humidity Measuring and Controlling Instruments) of the Instruments and Laboratory Equipment group. The manufacturer of record is Ametek, Inc. Dba Ametek Process & Analytical Instruments Div Process & Analytical Instruments Division. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Item Name | Hygrometer,dial Indicating |
| FSC / FSG | 6685 — Pressure, Temperature, and Humidity Measuring and Controlling Instruments (FSG 66) |
| Manufacturers | Ametek, Inc. Dba Ametek Process & Analytical Instruments Div Process & Analytical Instruments Division (CAGE 1PTE3) |
| Parameter | Value |
|---|---|
| NSN | 6685-01-460-5538 |
| Primary Part Number | 303B |
| Item Name | Hygrometer,dial Indicating |
| FSC / FSG | 6685 / 66 — Pressure, Temperature, and Humidity Measuring and Controlling Instruments |
| Manufacturer | Ametek, Inc. Dba Ametek Process & Analytical Instruments Div Process & Analytical Instruments Division |
| Status | ACTIVE |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | Possible hazard — SDS may be required (DLA HMIC P) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| 303B PRIMARY | Ametek, Inc. Dba Ametek Process & Analytical Instruments Div Process & Analytical Instruments Division (USA) |
| Reference | Meaning |
|---|---|
| 1988AS1159 | 5/9 Secondary reference Vertex Modernization and Sustainment Llc |
| 303B | 5/9 Secondary reference Ametek Inc Flange and Fitting Div |
| 1988AS1159 | D/9 Drawing number reference only Naval Air Systems Command Managed Original Design Activity Not Material/parts Supplier |
| 303B | 5/9 Secondary reference U.S. Government activity |
NSN 6685-01-460-5538 is a Hygrometer,dial Indicating, manufactured by Ametek, Inc. Dba Ametek Process & Analytical Instruments Div Process & Analytical Instruments Division, classified under FSC 6685, Pressure, Temperature, and Humidity Measuring and Controlling Instruments. Status: active.
NSN 6685-01-460-5538 has 1 manufacturer part number on file: 303B (Ametek, Inc. Dba Ametek Process & Analytical Instruments Div Process & Analytical Instruments Division).
1 possible match (shared part number, not a government interchangeability claim): 6630-01-563-3994. Verify interchangeability with system specifications before substitution.
Possible hazard — SDS may be required (DLA HMIC P). Hazard information on this page is shown exactly as it appears in the DLA record.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.