The Hygrothermograph, cataloged under National Stock Number 6685-01-558-8295, 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 Extech Instruments. Government technical data includes 3 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 6685-01-558-8295 |
| Primary Part Number | RH520 |
| Item Name | Hygrothermograph |
| FSC / FSG | 6685 / 66 — Pressure, Temperature, and Humidity Measuring and Controlling Instruments |
| Manufacturer | Extech Instruments |
| Status | ACTIVE |
| Mounting Facility Type and Quantity | 1 BASE AND 1 WALL |
| Measurement Type | DIGITAL |
| Voltage Rating in Volts | 110.0 AC NOMINAL |
| 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 |
|---|---|
| RH520 PRIMARY | Extech Instruments (USA) |
| Reference | Meaning |
|---|---|
| 10348277 | 6/9 Informative reference only Nimikkeistokeskus Ncb Finland |
NSN 6685-01-558-8295 is a Hygrothermograph, manufactured by Extech Instruments, classified under FSC 6685, Pressure, Temperature, and Humidity Measuring and Controlling Instruments. Status: active.
NSN 6685-01-558-8295 has 1 manufacturer part number on file: RH520 (Extech Instruments).
Key specifications for RH520: Mounting Facility Type and Quantity: 1 BASE AND 1 WALL; Measurement Type: DIGITAL; Special Features: DUAL LCD DISPLAY; RECORDS 49000 DATA POINTS; PAPERLESS; NUMERICAL AND GRAPHICAL DISPLAY; REPLACEABLE PROBE; AUDIBLE AND VISUAL ALARM WITH HI/LOW SETPOINTS; INCLUDES DETACHABLE PROBE W/3FT CABLE; RS232 CABLE, SOFTWARE, 110VAC ADAPTER AND 3AA BATTERIES VAC; Voltage Rating in Volts: 110.0 AC NOMINAL. 3 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.
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.