DS1921G Thermochron Temperature Logger
The workhorse cold-chain logger: 2048 timestamped readings plus a built-in histogram, −40 to +85 °C.
A complete data logger inside a Touch Memory can — clock, sensor, memory and a 10-year battery, with nothing to wire and nothing to charge. Beyond the 2048-point trend log it keeps a 63-bin histogram covering the whole range at 2 °C, so even after the log wraps you still hold the full statistical picture of the trip, plus 96 bytes of alarm memory that timestamps every excursion outside your limits and how long it lasted. Drop it in the shipment, read it out on arrival: the default choice when you need a defensible temperature record at the lowest cost per shipment.
The one with the histogram
Only the DS1921G keeps a 63-bin, 2 °C histogram of the entire mission independently of the trend log. Even when the 2048-point log wraps on a long trip, the histogram still tells you how much total time the load spent in each temperature band — the summary an auditor actually asks for. Choose it as the default, high-volume cold-chain logger; step up to the DS1922L only when you need finer accuracy or second-level sampling.
Key features
- Complete temperature logger in one button: clock, sensor, memory and battery — drop it in the shipment.
- 2048-sample log at 0.5 °C resolution, ±1 °C accuracy, NIST-traceable factory calibration, EN 12830 compliant.
- Programmable sampling 1–255 minutes; long-term histogram; records up to 24 timestamped alarm excursions.
- 512 bytes battery-backed SRAM for shipment data; 10-year minimum shelf life; family code 21h.
- IP56 water-resistant stainless steel (waterproof in a DS9107 capsule); CE / FCC / UL 913.
Specifications
| Chip / compatibility | DS1921G · family code 21h |
|---|---|
| Memory | 2048 timestamped readings + 63-bin histogram (2 °C) + 96 B alarm log + 512 B user memory |
| Operating temperature | −40 to +85 °C · 0.5 °C resolution · ±1 °C accuracy (−30…+70 °C) |
| Protocol | Sample rate 1–255 min; mission delay; roll-over or stop-when-full |
| Package | F5 stainless can · ~10-year battery, not replaceable |
| Options | Read out with DS9490R USB adapter + OneWireViewer; NIST-traceable calibration on request |
Inside the stainless can
A 0.25 mm solid stainless shell, a UV-stable polypropylene grommet isolating lid from base, and the die bonded inside. Lid = data contact, base = ground return.
Which logger should you order?
The four Thermochron / Hygrochron loggers side by side — specifications per the Analog Devices datasheets.
| DS1921G | DS1922L | DS1923 | DS1925 | |
|---|---|---|---|---|
| Measures | Temperature | Temperature | Temperature + humidity | Temperature |
| Range | −40 to +85 °C | −40 to +85 °C | −20 to +85 °C · 0–100 % RH | −40 to +85 °C |
| Accuracy | ±1 °C | ±0.5 °C | ±0.5 °C · ±5 % RH | ±0.5 °C |
| Best resolution | 0.5 °C | 0.0625 °C | 0.0625 °C · 0.04 % RH | 0.0625 °C |
| Log capacity | 2048 readings | 8192 readings (8 KB) | 8192 readings (8 KB) | 125,440 readings (122 KB) |
| Fastest sample rate | 1 min | 1 second | 1 second | 5 min |
| Histogram | Yes — 63 bins at 2 °C | — | — | — |
| Password protection | — | Two-level | Two-level | Two-level |
| Family code | 21h | 41h | 41h | 53h |
| Choose it when… | Volume cold-chain shipments, lowest cost per trip | Process validation, fast excursions, tight accuracy | Condensation, mould, corrosion — RH matters | Long ocean freight, year-long unattended missions |
Ordering information
| MOQ | 100 pcs |
|---|---|
| Lead time | 3–7 days for stock items, 10–15 days for OEM |
| Packing | Bulk ESD bags (100–200 pcs/bag, 2 bags/carton); blister or header cards for retail on request |
| Samples | Free samples for volume buyers — courier at cost |
| Payment | T/T bank transfer; other terms negotiable for repeat orders |
| Shipping | DHL / FedEx / UPS air express; sea or rail freight for pallet volumes |
| Customization | ROM ranges · housing colours · laser logo · private label |
Typical applications
Frequently asked questions
How many readings does the DS1921G store and at what resolution?
It logs 2048 temperature samples at 0.5 °C resolution, with ±1 °C accuracy from a NIST-traceable factory calibration. The sampling interval is programmable from 1 to 255 minutes, and optional rollover keeps the most recent 2048 readings.
Is the DS1921G waterproof and how long does the battery last?
The stainless-steel MicroCan is IP56 water-resistant and fully waterproof inside a DS9107 capsule. Shelf life is 10 years minimum; in use, battery life depends on sample rate and temperature — running continuously above +50 °C shortens it significantly.
Does the DS1921G support temperature alarms?
Yes. You can set high and low trip points, and the device records up to 24 timestamped excursion events with their durations, plus a long-term temperature histogram. It is EN 12830 compliant for cold-chain use.
Related products
DS1922L High-Resolution Temperature Logger
±0.5 °C accuracy and 0.0625 °C resolution, sampling as fast as once per second.
DS1923 Hygrochron Temperature + Humidity Logger
The only iButton that logs relative humidity — 0–100 % RH alongside temperature, from one sealed can.
DS1925 High-Capacity Long-Mission Logger
125,440 timestamped readings — 15× the DS1922L, enough for a year-long mission at one point per 5 min.