Additional safety information

This section provides information about the safe use of the instrument, wireless channels, and disposal of batteries.

Laser safety labels

The instrument has two laser safety labels: one inside the case and one on the back of the case.

Warning: The use of controls, adjustments, or the performance of procedures other than those specified herein may result in hazardous radiation exposure.

The LI-7820 is certified as a Class I laser product. No hazardous radiation is emitted from the instrument. Any laser radiation emitted is below the Class I laser limits during all phases of user operation. The laser emits (internally only) at approximately 2121 nm and has a Class 1M peak power rating of up to 75 milliwatts but is permanently set to <15 mW. This instrument complies with the CDRH regulations for laser products (CDRH radiation performance standard 21, Code of Federal Regulations Chapter 1, Subchapter J). Compliance for products marketed in the United States is mandatory.

Figure B‑1. The Class 1 laser safety label is affixed to the back of the case.
Figure B‑2. The laser radiation safety label is inside the instrument case.

Wireless communication notice

The instrument is equipped with wireless communication (Wi-Fi™) capabilities. Wi-Fi communication conforms to the requirements in this section. See Connecting over wireless for more details.

Channel Number Lower Frequency (mHz) Center Frequency (mHz) Upper Frequency (mHz)
1 2401 2412 2423
2 2406 2417 2428
3 2411 2422 2433
4 2416 2427 2438
5 2421 2432 2443
6 2426 2437 2448
7 2431 2442 2453
8 2436 2447 2458
9 2441 2452 2463
10 2446 2457 2468
11 2451 2462 2473

Radio transmission power is given in Table B‑1.

Table B‑1. Radio transmission power.
Network Type Transmission Power
802.11b 10.5 dBm
802.11g/n 11 dBm

Battery warnings and disposal

Wheelie bin symbol indicates that the product should be discarded to electronics waste collection rather than household waste.

The instrument includes rechargeable lithium ion batteries and CR lithium batteries, which must be disposed of safely. The primary batteries are accessible through the battery cover on the case. The coin-cell batteries are in the case under an electronics shroud.

Warning: Lithium ion batteries may cause environmental damage or damage to human health if they are disposed of improperly. Do not dispose of the batteries in unsorted municipal waste or an incinerator. Many localities have battery recycling facilities that will accept lithium ion batteries. Check your local regulations to determine how to safely dispose of the batteries.

Primary batteries

To remove the primary batteries, turn the clasp counter-clockwise ¼ turn to open the battery door. Grasp the tab on the battery and pull to remove the battery. There is space for two batteries. Be sure to remove both of them.

The battery door is on the side of the case.

Coin-cell battery

The product includes a CR Lithium coin-cell battery, which contains perchlorate material. Special handling may apply. In the U.S. State of California, see

To remove the coin-cell batteries, power off the instrument, remove the batteries, and open the lid to the case. Remove the four screws that secure the electronics shroud. Being careful to avoid straining the Wi-Fi antenna (it is glued to the shroud), move the shroud to the side. The battery is near the middle of the instrument. The battery is held in with friction. Press it out. Insert a replacement battery with the positive (+) pole facing up.

Remove the electronics cover to access the coin-cell battery.
Figure B‑3. Carefully lift the shroud as shown to avoid straining the Wi-Fi antenna, which is attached to the shroud.