Michael John Philpot, 58, was sentenced in the ACT Supreme Court on Wednesday on one charge of using a carriage service to solicit child pornography.

Philpot first met the 13-year-old boy on social networking application Grindr.

The pair chatted and then switched to texting, sending explicit messages for almost three months.

The boy's mother told the court on Wednesday that the emotional scars of Philpot's actions would "remain forever".

"Our lives have become fragile and fractured," she said.

Philpot's crime came to light in April 2013, when the Catholic Education Office confiscated his school-issued iPhone, iPad and laptop.

Police were called and later went to the boy's mother, who said the knock on her door was the start of an unimaginable journey.

She said her son had turned from a happy, fun child, to one who was angry, required counselling, and self-harmed.

"The scarring on our son's arms and legs are something that will fade over time," she said.

"But the emotional scars will last forever."

Chief Justice Helen Murrell sentenced Philpot to 19 months' imprisonment, but released him immediately on a recognisance order, which requires a security of $1000, two-and-a-half years of good behaviour, counselling, and supervision by ACT Corrective Services.

Philpot gave evidence about his actions on Wednesday, saying he was ashamed and disgusted with himself, but that he had been undergoing counselling to understand the reasons behind the crime.

"I've been a school teacher and principal for 13 plus years ... I would never, ever do anything to hurt a child," he said.

The judge remarked that it appeared obvious to everyone except the offender that his actions were designed to achieve sexual gratification.

Philpot expressed remorse to the young person and his family, some of whom were sitting in the courtroom as he gave evidence.

"The actions that I have taken have no doubt caused a great deal of pain for them over a number of years," he said.

The former principal conceded he had known the child was under 18, but said he had not known his true age – 13 and later 14 – until police told him. It was a revelation he described to the court as "devastating".

Philpot conceded he was in a position of trust within the community, and had let a lot of people down.

"A lot of people put their faith in me and their trust in me and I have clearly broken that trust," he said.

His lawyers submitted he had already been punished, by being named and shamed in local media, and through the loss of his job and income.

But Chief Justice Murrell said that submission "cut both ways", saying Philpot only had such a long way to fall because he had been in a position of trust and esteem in the community.

Philpot had also argued the offences stemmed from a time of psychological and work-related stress.

But the judge told Philpot his position in the Catholic education system, which she described as "notorious" for predatory behaviour, should have made him acutely aware of the psychological immaturity and vulnerability of children.

"In no way do the offender's psychological circumstances excuse his conduct," she said.

Philpot's wife, Jennifer Philpot, also gave evidence in the sentencing proceedings, saying she still supported her husband.

Mrs Philpot said the publicity arising from the case had been "terrible".

"To live with it in a small town is particularly hard," she said.

Chief Justice Murrell said the community would be best served by a sentence that allowed Philpot to continue his rehabilitation, while acknowledging the harm to the victim, the need for general deterrence, denunciation, and punishment.