HTP312 Balance Support: Manual, Calibration & Troubleshooting
Everything you need to set up, calibrate and troubleshoot the Fristaden Lab HTP312 precision balance (1 kg, 2 kg, 3 kg and 10 kg models, 0.01 g readability).
Download the HTP Series user manual (PDF)
Quick start
- Snap the weighing pan onto the base. Round-pan models include an ABS windshield.
- Connect the power cord and plug into a 100–240 V outlet.
- Level the balance by screwing the feet in or out until the bubble is centered.
- Press POWER. The display lights fully, then counts 1 to 9 and settles at 0.
- Let the balance warm up for 15–30 minutes for best accuracy, then calibrate.
Buttons
| Button | Short press | Long press |
|---|---|---|
| POWER | On / off | – |
| TARE/CAL | Tare (zero out a container) | Start calibration |
| UNIT | Switch g, ct, oz, lb | – |
| PCS | Counting mode | – |
How to calibrate the HTP312
The balance auto-detects calibration weights in multiples of 100 g (200 g, 500 g, 1000 g and so on) up to its capacity. For 2000 g and larger models, use at least 500 g; the closer the weight is to the balance's capacity, the more accurate the result. 0.01 g models include a 500 g calibration weight.
- Turn the balance on and let it settle at zero.
- Long-press TARE/CAL until CAL appears.
- The display shows a weight. Place your calibration weight in the center of the pan; the balance detects it automatically.
- When the reading is stable and correct, remove the weight.
On first use, repeat calibration 2–3 times with the balance level and still. If readings are still off after that, contact us before returning the unit.
Linear (multi-point) calibration
If readings drift across the range over time, run a 3-point linear calibration (zero, half and full range):
- Turn the balance on, then press TARE/CAL twice and PCS once.
- When 01-diu appears, press UNIT until 04-CAL shows, then press TARE/CAL.
- Press UNIT to choose CAL3 and confirm with TARE/CAL.
- Place each standard weight the display asks for. When it stabilizes, remove it and place the next.
- Calibration is complete when the display returns to 0.
Tare and counting
Tare: place an empty container on the pan, press TARE/CAL until 0 shows, then add your sample to see net weight. Press TARE/CAL again to reset.
Counting: press PCS and choose 10, 20, 50 or 100. Place that many identical pieces on the pan and press PCS again. Add or remove pieces and the display shows the count. Press UNIT to exit. Counting is unreliable for very light or non-uniform parts.
Error messages and troubleshooting
| What you see | Likely cause | Fix |
|---|---|---|
| OVER or OL | Overloaded, or calibration error | Remove weight. If OL persists with an empty pan, check the pan sits on its support, then recalibrate. |
| Reading won't settle / decimal point flashes | Drafts, vibration, something touching the pan, temperature swings, unstable power | Close doors and vents, move away from vibrating equipment, check nothing is under the pan, use a voltage stabilizer. |
| Large weighing error | Out of calibration | Check against a known weight and recalibrate (linear calibration if needed). |
| Display won't turn on | Loose or damaged power cord | Reseat both ends of the cord or replace it. |
| Display frozen during weighing | Sensor locked | Tap the pan gently. If there's no response, contact support. |
RS-232 (computer connection models)
- Power on and, before it zeroes, press TARE/CAL twice and PCS once.
- At 01-diu, press UNIT until 09-odE appears; press TARE/CAL.
- Choose output mode: 2 sends one reading when the weight stabilizes, 3 sends continuously, 1 responds to the PC command “R”. Confirm with TARE/CAL and restart the balance.
- Default baud rate is 9600 (change it under 08 in the same menu). Match it in your PC software.
Batteries and data cables are not included.
Care
Unplug before cleaning. Wipe with a damp cloth and mild detergent, then dry. Never use solvents or immerse the balance. Keep it away from direct sunlight, drafts and equipment that causes electromagnetic interference, and operate between 40 °F and 105 °F.
Still need help?
Your balance is covered by a 1-year warranty. Email support@fristadenllc.com or use our contact form. Need a calibration certificate? See how calibration certificates work.
