Digital probe thermometers are a wise investment, since they can be used in every type of production, not only frozen desserts. They are battery operated and water resistant (some models are waterproof). The probe connects to the body of the thermometer, where an accurate reading is displayed after a few seconds of immersing the probe. Instant-read thermometers are ideal. They have highly sensitive probes that give real-time readings, as opposed to having to wait to get an accurate reading. During those few seconds, temperatures can escalate and compromise the final product. The only downside is that they can be expensive, but accuracy is well worth the extra money.