The Hygrometer,digital, cataloged under National Stock Number 6685-01-441-0577, 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 Naval Air Systems Command Managed Original Design Activity Not Material/parts Supplier. Government technical data includes 13 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 6685-01-441-0577 |
| Primary Part Number | 639AS9334-2 |
| Item Name | Hygrometer,digital |
| FSC / FSG | 6685 / 66 — Pressure, Temperature, and Humidity Measuring and Controlling Instruments |
| Manufacturer | Naval Air Systems Command Managed Original Design Activity Not Material/parts Supplier |
| Status | ACTIVE |
| Phase | SINGLESINGLE |
| Frequency in Hertz | 60.060.0 |
| Display Digit Quantity | 1616 |
| Relationship to Similar Equipment | 639AS9334-1 INCLUDES NICAD BATTERIES, THIS NSN DOES NOT. MAY BE USED IN LEU OF CGU-26 TO CHECK GAS FOR MOISTURE CONTENT |
| Style Designator | PORTABLE, BENCH |
| Case Type | WATERPROOF AND WATERPROOF AND SHOCKPROOF CASE W/HANDLESHOCKPROOF CASE W/HANDLE |
| Display Type | LIQUID CRYSTALLIQUID CRYSTAL |
| Operating Temp Range | -15.0 TO 60.0 CELSIUS-15.0 TO 60.0 CELSIUS DEGC |
| Functional Description | A COMPACTPORTABLE HYGOMETER, ABLE TO CHECK THE MOISTURE CONTENT OF ANY GAS UP TO 6000 PSI PRESSURE. THE HYGROMETER DISPLAYS THE DEWPOINT OF THE GAS IN DEGREES CELCIUS OR THE WATER CONTENT OF THE GAS IN PARTS PER MILLION.A COMPACTPORTABLE HYGOMETER, ABLE TO CHECK THE MOISTURE CONTENT OF ANY GAS UP TO 6000 PSI PRESSURE. THE HYGROMETER DISPLAYS THE DEWPOINT OF THE GAS IN DEGREES CELCIUS OR THE WATER CONTENT OF THE GAS IN PARTS PER MILLION. |
| Environmental Attribute Code | BAROMETERS & HYGROMETERS - CONSUMER PRODUCTS - NON-MERCURY ALTERNATIVEBAROMETERS & HYGROMETERS - CONSUMER PRODUCTS - NON-MERCURY ALTERNATIVE |
| Material | PLASTIC CARRYING CASE |
| Type/model Designation | TTU-546/E |
| Voltage Rating in Volts | 100.0 AC MINIMUM AND 100.0 AC MINIMUM AND 240.0 AC MAXIMUM240.0 AC MAXIMUM |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL Q — CCL Item — Commerce Control List |
| Hazard | Possible hazard — SDS may be required (DLA HMIC P) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| 639AS9334-2 PRIMARY | Naval Air Systems Command Managed Original Design Activity Not Material/parts Supplier (USA) |
| Reference | Meaning |
|---|---|
| TTU-546/E | 5/2 Secondary reference U.S. Government activity |
| 639AS9334 | D/9 Drawing number reference only Naval Air Systems Command Managed Original Design Activity Not Material/parts Supplier |
NSN 6685-01-441-0577 is a Hygrometer,digital, manufactured by Naval Air Systems Command Managed Original Design Activity Not Material/parts Supplier, classified under FSC 6685, Pressure, Temperature, and Humidity Measuring and Controlling Instruments. Status: active.
NSN 6685-01-441-0577 has 1 manufacturer part number on file: 639AS9334-2 (Naval Air Systems Command Managed Original Design Activity Not Material/parts Supplier).
Key specifications for 639AS9334-2: Overall Height: 15.500 INCHES NOMINAL15.500 INCHES NOMINAL IN; Phase: SINGLESINGLE; Frequency in Hertz: 60.060.0; Display Digit Quantity: 1616. 13 specifications are documented in the U.S. Government catalog.
Possible hazard — SDS may be required (DLA HMIC P). Hazard information on this page is shown exactly as it appears in the DLA record.
NSN 6685-01-441-0577 has DEMIL Code Q. Demilitarization may be required before disposal or transfer to non-military entities.
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.