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.
The capacity problem solved. On a long ocean crossing or a multi-month warehouse mission, an 8 KB logger must either sample coarsely or roll over and overwrite the beginning of the trip — exactly the part an insurance claim asks about. With 122 KB of data-log memory the DS1925 stores 125,440 timestamped values at ±0.5 °C, so a fine sample interval and a complete unbroken record are no longer mutually exclusive. It also reports its own remaining battery level, and will still output logged data if the battery has since been depleted — the record survives even when the device does not.
The one that never runs out of memory
122 KB versus 8 KB — fifteen times the memory of a DS1922L. On an 80-day sea freight at one reading every 15 minutes an 8 KB logger overwrites the first two-thirds of the voyage; the DS1925 holds all 7,680 points with room to spare, or lets you sample every 5 minutes for a full year. It is also the only one of the four that reports its remaining battery level and can still output its log after the battery has died. Choose it whenever the mission is long, unattended, or the beginning of the record matters as much as the end.
Key features
- Highest-capacity iButton logger: up to 125,440 timestamped readings (122 KB) — 122K in 8-bit or 61K in 16-bit mode.
- Purpose-built for long-duration missions with short sample intervals (5 min to 273 hr).
- 0.0625 °C (16-bit) resolution, ±0.5 °C accuracy; RTC ±1 minute/month at +25 °C.
- Reports internal battery level and still outputs logged data even after the battery is depleted.
- Two-level password protection; durable stainless steel; family code 53h; −40 to +85 °C.
Specifications
| Chip / compatibility | DS1925 · family code 53h |
|---|---|
| Memory | 122 KB data log = 125,440 timestamped values (122K 8-bit or 61K 16-bit) + 512 B user memory |
| Operating temperature | −40 to +85 °C · ±0.5 °C measurement accuracy |
| Protocol | Sample rate 5 min to 273 h; start immediately, after a delay, or on a temperature alarm; two-level password protection |
| Options | Reports internal battery level; outputs logged data even after the battery is depleted |
| Package | F5 stainless can · storage or operation above +50 °C significantly shortens battery life |
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 much longer can a DS1925 record than a DS1922L?
About fifteen times: 122 KB of data-log memory holding 125,440 timestamped values, against 8 KB and 8192 readings. In practice that means you can keep a 5-minute sample interval for roughly a year, or cover an 80-day sea crossing at 15-minute intervals with the whole voyage intact rather than overwriting its first two-thirds. Its minimum interval is 5 minutes, so for second-by-second work the DS1922L is still the right tool.
What happens if the battery dies during a long mission?
The DS1925 is designed for exactly this risk. It measures and reports its own internal battery level, so you can check the remaining capacity before committing it to a long mission, and it will still output the logged data even after the battery has been depleted — the record survives the device. Note that storing or operating it above +50 °C shortens battery life significantly, so keep spare stock cool.
Related products
DS1921G Thermochron Temperature Logger
The workhorse cold-chain logger: 2048 timestamped readings plus a built-in histogram, −40 to +85 °C.
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.