Acurite Atomic Clocks

Models 75440, 13131, 75077A3M, and 01121M explicitly describe atomic radio time. The 75440 attributes synchronization to the NIST signal, 13131 lists four US zones, and 01121M also applies daylight-saving changes. Reception schedule, supported zones, and manual fallback are not complete across all four, so automatic setup still needs model-specific verification.

Models 13027A4, 01129M, 75173M, 13019W2, and 13040CA use Intelli-Time language. Their descriptions focus on stored or preprogrammed time behavior, outage recovery, alarm retention, or automatic daylight-saving updates rather than radio reception. The 02418 analog wall-clock record establishes neither atomic setting nor Intelli-Time. Check the exact method instead of treating automatic DST, retained memory, and WWVB reception as interchangeable. A clock can apply DST without ever receiving a radio signal.

Model 13027A4 concentrates on LED time, brightness, alarm, and snooze. The 75173M jumbo LCD shows hour, minute, and second without documented weather or alarm functions. Model 13019W2 adds two alarm-volume and dimmer settings. The 13040CA includes date, indoor temperature, humidity, and moon phase but no outdoor thermometer. Model 13131 shows indoor temperature, date, and weekday on a momentarily lit LCD.

Models 75440, 01129M, 75077A3M, and 01121M add outdoor-sensor data. The last three present forecasts, while 01121M adds barometric pressure, highs and lows, and programmable weather thresholds. The 02418 title names analog thermometer and hygrometer dials, but its saved description does not substantiate their ranges. Compare digit size, viewing angle, nighttime lighting, sensor package, transmission range, tolerance, and information visible without pressing a light button.

Battery operation does not imply the same outage behavior. Model 13131 needs three AA cells and 75173M needs four. The 75440, 75077A3M, and 01121M are wireless or sensor-based, yet their complete display and sensor power requirements are missing. Models 13027A4, 13019W2, and 13040CA discuss retained time or alarms during power loss without supplying every backup-cell detail.

Placement also varies. The 75440, 75077A3M, and 01121M can stand or hang. Model 13131 and the alarm clocks are tabletop designs. The 75173M and 02418 are wall clocks, although 75173M does not document its rear hanger. Ask whether adapters, sensors, batteries, stands, keyholes, or wall fasteners are included. Confirm rear clearance and sensor siting before installation because retained settings, a visible screen, and an audible alarm are different outcomes when mains power fails.

Model 13131 has five-by-seven-inch body dimensions, a three-by-five-inch display, and an unexplained 0.5 title value. Model 13019W2 supplies only a 5.4-inch figure without identifying width, height, or display size. The 75173M headline says 13.5 inches without complete outer dimensions. Model 01121M omits display and sensor dimensions, power requirements, measurement tolerances, and exact package contents.

The 02418 Walmart description is generic and does not substantiate atomic operation, sensors, construction, batteries, or weather protection. Do not fill those gaps from another AcuRite model. Reconcile item number, model label, full dimensions, atomic or memory method, sensor inclusion, power accessories, mounting, exposure limits, warranty, seller, and returns. Sparse or contradictory fields should remain explicit uncertainty, especially where adjacent models share a brand but use different displays, sensors, batteries, and setting systems.