Data sheet: ohmSTAR and ohmSTAR+
LabMetric · Data sheet
ohmSTAR and ohmSTAR+
Precision programmable resistors. Same idea, two ranges.
Range
1 Ω – 25 MΩ
ohmSTAR
1 Ω – 5 MΩ
ohmSTAR+
Resolution
0.1 Ω
ohmSTAR
0.01 Ω
ohmSTAR+
Accuracy, 1 kΩ–1 MΩ
±0.1 %
ohmSTAR
±0.05 %
ohmSTAR+
Switching
Mechanical relays
Full relay isolation
Both models
Real resistance, set any way you like
ohmSTAR and ohmSTAR+ replace the decade box. Set a resistance from the keypad, the knob, a stored value or a computer, and the box puts that real resistance on its terminals. Every value is switched by latching relays and precision fixed resistors, so the circuit inside is isolated from your output. Neither model is better: ohmSTAR goes higher, ohmSTAR+ steps finer.
Features
- Keypad, knob and USB control
- 4 quick keys (A–D) and 10 memories
- Current limiter (I set) protects the 1 W rating; the open key disconnects the output mechanically
- Sensor tables: set °C or another unit and see it with the ohms on the graphic LCD
- Field calibration against a reference meter
- Battery powered, over 1 year battery life
- The ohmSTAR Companion desktop app, and firmware updates over USB
- One set of test leads included
Applications
- Instrument and controller calibration
- Automated test equipment (ATE)
- HVAC controls
- PLC and process control
- Product development
- Education
Simulates platinum RTDs, NTC thermistors, strain gauges, conductivity cells and potentiometric sensors, or anything you can write as a table.
ohmSTAR and ohmSTAR+ data sheet
LabMetric
Specifications
| Parameter | ohmSTAR | ohmSTAR+ |
|---|---|---|
| Range | 1 Ω to 25 MΩ | 1 Ω to 5 MΩ |
| Resolution | 0.1 Ω | 0.01 Ω |
| Accuracy at 25 ±2 °C | ±0.5 Ω below 1 kΩ ±0.1 % from 1 kΩ to 1 MΩ ±0.5 % above 1 MΩ | ±0.2 Ω below 1 kΩ ±0.05 % from 1 kΩ to 1 MΩ ±0.5 % above 1 MΩ |
| Power rating | 1 W max | |
| Switching | Mechanical relays, full relay isolation | |
| Protection | Current limiter (I set). Open key disconnects mechanically. | |
| Control | Keypad, encoder wheel, USB | |
| Memory | 4 quick keys (A–D), 10 memories | |
| Display | Graphic LCD; unit and resistance together | |
| Sensor types | Pt RTD, NTC thermistor, strain gauge, conductivity, potentiometric, custom table | |
| Power | Battery. Over 1 year battery life. | |
| Size and weight | 6.7 × 3.5 × 1.6 in (17 × 8.7 × 4.1 cm), 13.8 oz (392 g) | |
| Included, warranty | One set of test leads. Lifetime warranty, original US purchaser. | |
ohmSTAR Companion
Windows 10+, macOS 13+ (Apple silicon)
- Live front panel and keypad, memories, box settings
- Sweeps, pass/fail sequences, CSV logging
- 128 sensor curves, temperature to ohms, custom tables
- Several boxes, command line, local network API
- AI assistant that asks first; AI control over MCP
- Calibration bench and one-page certificate
Firmware 7.x
Both models
- Updates and repair over USB from the Companion
- Knob pickers on I set and Step
- Memory list of all 14 values
- Table list, standby delay, display-off mode
- Serial, calibration due date and use count
Works with either model on firmware 7.x. Older boxes: a one-time upgrade by mail. Full list: labmetric.com/software-downloads
Interfaces
USB serial, 9600 baud, 8N1: for the Companion, your scripts and any terminal. The Companion adds a local network API and MCP for AI agents on the same computer.
Ordering
| Model | Price |
|---|---|
| ohmSTAR | $987 |
| ohmSTAR+ | $1,024 |
One set of test leads included. Schools: 30% off. Accessories: a second set of test leads $28, IV Pole Clamp $16, anodized aluminum knobs (set of 6) $12.89.
LabMetric · Scottsdale, Arizona
mmasano@gmail.com
602-751-5848
labmetric.com